MultiBlend
CLINICAL STUDIES ON THE FOLLOWING INGREDIENTS:
VITAMIN A
Vitamin A in Skin and Hair: An Update
Abstract
Vitamin A is essential for the health of skin and hair, with both deficiency and excess having negative effects. Its bioactive forms, retinoic acid and retinal, play critical roles in regulating hair follicle stem cells and influencing hair cycles, melanocyte activity, and wound healing. This review synthesizes current research on retinoid biology and their effects on skin and hair health, highlighting the need for careful management of Vitamin A levels.
Methods: The article discusses recent findings on Vitamin A metabolism, the impact of retinoids on hair follicle stem cells and the hair cycle, and the effects of UV irradiation on retinoid metabolism in skin cells. It draws on experimental studies and clinical observations to provide a comprehensive update on retinoid functions.
Results: Findings indicate that retinoids regulate hair growth cycles in a dose-dependent manner, influence melanocyte differentiation, and are crucial in skin wound healing. Exposure to UV radiation negatively affects retinoid levels, leading to potential implications for skin health.
Conclusion: Retinoids are vital for maintaining healthy skin and hair, with careful management of Vitamin A intake necessary to harness their benefits while avoiding toxicity. Further research is needed to clarify retinoid functions in melanocytes and identify sources for retinal involved in phototransduction.
Sources: Christine A VanBuren, Helen B Everts. Vitamin A in Skin and Hair: An Update. PMCID: PMC9324272, PMID: 35889909.
The effect of vitamin A supplementation on thyroid function in premenopausal women
Abstract
Objective: Vitamin A and its retinoid derivates play an important role in regulation of normal growth and development. Vitamin A has been shown to regulate thyroid hormone metabolism and inhibit thyroid-stimulating hormone (TSH) secretion via down regulation of TSH-β gene expression; however, the effect of vitamin A on thyroid function in obese individuals who are at higher risk of subclinical hypothyroidism is still unclear. In the present study we investigate the impact of vitamin A supplementation on thyroid function in obese women.
Method: A 4-month randomized, double blind controlled trial was conducted among 84 healthy women aged 17-50 years old: 56 were obese (body mass index [BMI] 30-35 kg/m(2)) and 28 were nonobese (BMI 18.5-24.9 kg/m(2)). Obese women were randomly allocated to receive either vitamin A (25,000 IU/d retinyl palmitate) or placebo. Nonobese women received vitamin A. At baseline and 4 months after intervention, serum concentrations of TSH, total thyroxine (T4), total triiodothyronine (T3), retinol-binding protein (RBP), and transthyretin (TTR) were measured.
Results: Baseline concentrations of thyroid hormones, RBP and TTR were not significantly different between groups. Vitamin A caused a significant reduction in serum TSH concentrations in obese (p = 0.004) and nonobese (p = 0.001) groups. Serum T3 concentrations also increased in both obese and nonobese vitamin A-treated groups (p < 0.001). Serum T4 decreased in all 3 groups after treatment. The results showed a significant reduction in serum RBP in the obese group after vitamin A supplementation (p = 0.007), but no significant change was seen in serum TTR.
Conclusions: Serum TSH concentrations in vitamin A-treated subjects were significantly reduced; therefore, vitamin A supplementation might reduce the risk of subclinical hypothyroidism in premenopausal women.
Source: Farhangi MA, Keshavarz SA, Eshraghian M, Ostadrahimi A, Saboor-Yaraghi AA. The effect of vitamin A supplementation on thyroid function in premenopausal women. J Am Coll Nutr. 2012 Aug;31(4):268-74. doi: 10.1080/07315724.2012.10720431. PMID: 23378454.
VITAMIN C
Vitamin C and Immune Function
Abstract
This article explores the essential role of Vitamin C as a micronutrient in supporting both the innate and adaptive immune systems. It acts as a potent antioxidant and a cofactor for biosynthetic and gene regulatory enzymes. Vitamin C enhances epithelial barrier functions and protects against oxidative stress, helps phagocytic cells like neutrophils with microbial killing, and aids in recycling neutrophils at infection sites to minimize tissue damage. While its role in lymphocyte activity is less defined, it promotes B- and T-cell differentiation and proliferation. Vitamin C deficiency is linked to weakened immunity and a higher risk of infections. During infections, Vitamin C levels decrease due to increased metabolic needs. Supplementation with Vitamin C can prevent and manage respiratory and systemic infections, with prevention requiring 100-200 mg/day and treatment needing higher doses to meet increased demands.
Methods: The article reviews existing research on the biosynthetic and immune-regulatory roles of Vitamin C in humans, particularly focusing on its antioxidant properties, impact on cellular immune functions, and requirements during infections.
Results: Vitamin C enhances various immune functions, prevents oxidative damage, and assists in controlling infections. Adequate daily intake can prevent infections, while high dosages may be required for treatment.
Conclusion: Vitamin C is crucial for maintaining immune defense functions. Sufficient daily intake is essential for infection prevention, and higher doses are beneficial during infections to cope with inflammatory and metabolic demands.
Sources: Anitra C Carr, Silvia Maggini. Vitamin C and Immune Function. Nutrients, Volume 9, Issue 11, Article 1211, DOI: 10.3390/nu9111211.
The Roles of Vitamin C in Skin Health
Abstract
This review examines the role of Vitamin C in maintaining skin health, highlighting its functions in collagen synthesis and antioxidant protection against UV-induced damage. The skin's structure, with its barrier-providing epidermal layer and supportive dermal layer, relies on high Vitamin C levels for optimal functionality. The paper discusses the effectiveness of dietary Vitamin C intake versus topical application, emphasizing the need for more research to evaluate the benefits of Vitamin C on skin properties.
Methods: The article reviews both in vitro and in vivo research focusing on Vitamin C's contribution to skin health, comparing the effectiveness of dietary intake versus topical application, and identifying gaps in current evidence.
Results: Vitamin C plays a crucial role in collagen production and offers antioxidant protection. While topical applications of Vitamin C are common, their efficacy compared to dietary intake needs further investigation. Some skin properties are likely to benefit more from adequate nutritional Vitamin C.
Conclusion: Vitamin C is essential for skin health, with potential benefits in UV protection and skin structure support. More evidence is needed to fully understand the comparative effectiveness of dietary intake and topical application, as well as to identify the most responsive skin properties.
Sources: Juliet M Pullar, Anitra C Carr, Margreet C M Vissers. The Roles of Vitamin C in Skin Health. Nutrients, Volume 9, Issue 8, Article 866, DOI: 10.3390/nu9080866.
Vitamin C for preventing and treating pneumonia
Abstract
This review examines the prophylactic and therapeutic effects of Vitamin C on pneumonia, a significant cause of morbidity and mortality. It includes analysis of several trials, mainly targeting community-acquired pneumonia in various populations. The results indicate that Vitamin C supplementation may significantly reduce the incidence of pneumonia in some groups, particularly where dietary Vitamin C intake is low. Therapeutically, higher doses of Vitamin C appear beneficial for patients with pneumonia, particularly those with low plasma levels.
Methods: The authors systematically searched various databases, including CENTRAL, MEDLINE, EMBASE, and Web of Science, for controlled trials assessing the effects of Vitamin C on pneumonia. They included both prophylactic and therapeutic studies and independently extracted data from selected trials.
Results: Three prophylactic trials showed an 80% or greater reduction in pneumonia incidence among Vitamin C supplementation groups. In two therapeutic trials, Vitamin C administration led to reduced duration and severity of pneumonia and lower mortality rates in severely ill patients. However, the evidence for hospital-acquired pneumonia was inconclusive.
Conclusion: The review found promising evidence suggesting that Vitamin C may prevent pneumonia in high-risk populations and improve outcomes in Vitamin C deficient pneumonia patients. Further research is needed to clarify its effects and establish guidelines for widespread prophylactic use in the general population.
Sources: Harri Hemilä, Pekka Louhiala. Vitamin C for preventing and treating pneumonia. Cochrane Database of Systematic Reviews, DOI: 10.1002/14651858.CD005532.pub3. Published on August 8, 2013.
Effect of Vitamin C Supplements on Respiratory Tract Infections: A Systematic Review and Meta-Analysis
Abstract
The review investigates the effectiveness of Vitamin C supplementation in preventing and treating respiratory tract infections (RTIs), a significant cause of morbidity and mortality globally. It involves a systematic analysis of placebo-controlled trials to assess Vitamin C's impact on the incidence, severity, and duration of respiratory illnesses.
Methods: The authors conducted a thorough search using Cochrane, PubMed, and MEDLINE Ovid databases. They included ten randomized controlled trials that met their criteria, performing random effects meta-analyses to evaluate the pooled effects of Vitamin C supplementation.
Results: Out of 2758 potential studies, ten were included in the analysis. The pooled risk ratio (RR) for developing respiratory illness with regular Vitamin C supplementation was 0.94 (95% CI: 0.87 to 1.01), suggesting a potential reduction in illness occurrence, albeit statistically insignificant (P = 0.09). The analysis showed no consistent effect of Vitamin C on the severity of respiratory illness (SMD 0.14, 95% CI: -0.02 to 0.30, I² = 22%, P = 0.09). However, the duration of respiratory infections was significantly shorter in the Vitamin C group (SMD -0.36, 95% CI: -0.62 to -0.09, P = 0.01).
Conclusion: Vitamin C supplementation may help reduce the duration of respiratory tract infections, though its influence on the incidence and severity remains unclear. The review emphasizes the need for more trials examining therapeutic dosages of Vitamin C in relation to respiratory infections.
Sources: Tahmina Afrose Keya, Anthony Leela, Kevin Fernandez, Nasrin Habib, Mumunur Rashid. Effect of Vitamin C Supplements on Respiratory Tract Infections: A Systematic Review and Meta-Analysis. PMID: 34967304, DOI: 10.2174/2772432817666211230100723.
Role of Vitamin C in Osteoporosis Development and Treatment—A Literature Review
Abstract
Osteoporosis, characterized by low-energy fractures, is a significant clinical issue, particularly among the elderly. This review evaluates the potential role of Vitamin C in osteoporosis prevention and treatment, focusing on its effects on bone metabolism. Despite the established importance of calcium and Vitamin D, emerging evidence suggests that Vitamin C may also play a crucial role. The review synthesizes findings from 82 studies, indicating the need for adequate Vitamin C intake to support bone health and combat osteoporosis.
Methods: A literature search was conducted using the PubMed/Medline database for studies published between January 2000 and May 2020. Keywords related to Vitamin C, bone metabolism, and osteoporosis were utilized to identify relevant articles, resulting in the inclusion of 66 studies encompassing observational and interventional research.
Results: Evidence from animal and observational studies reveals that Vitamin C is essential for collagen synthesis and bone mineralization. Regular Vitamin C supplementation has been correlated with improved bone mineral density (BMD) and reduced fracture risk, particularly in older populations. However, the review highlights the necessity of further research to clarify the benefits of Vitamin C supplementation in individuals without significant deficiency, as the existing clinical trials show variability in outcomes.
Conclusion: While current evidence supports the role of Vitamin C in bone metabolism and its potential to mitigate osteoporosis, the results of clinical trials remain inconsistent. A balanced diet rich in Vitamin C is beneficial for bone health, and further well-designed studies are needed to confirm its efficacy as a treatment or preventative measure against osteoporosis.
Sources: Olga Brzezińska, Zuzanna Łukasik, Joanna Makowska, Konrad Walczak. Role of Vitamin C in Osteoporosis Development and Treatment—A Literature Review. Nutrients, Volume 12, Issue 8, Article 2394; DOI: 10.3390/nu12082394.
Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and Echinacea in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds—Practical Advice on Dosages and on the Time to Take These Nutrients/Botanicals in order to Prevent or Treat Common Colds
Abstract
This review assesses the roles of vitamins C and D, zinc, and Echinacea in lowering the incidence, severity, and duration of common colds (CC). It includes evidence-supported preventive roles in immune clusters and CC treatment dosages. Regular vitamin C supplements (1-2g/day) reduce CC duration and severity, with zinc potentially shortening colds by 33% if taken within 24 hours of symptom onset. Vitamin D lowers CC risk, especially beneficial for those deficient or not on bolus doses. Prophylactic Echinacea (2400mg/day) reduces CC risk over 4 months.
Methods: A systematic review, following Egger et al.'s methodological steps, involved skilled clinicians and nutritionists. A structured PubMed search was performed for studies over the past 30 years, reviewed in English, on the roles of vitamin D, vitamin C, zinc, and Echinacea across three immune clusters for CC prevention and treatment.
Results:
Zinc: Shortens CC duration by 33%; crucial within 24 hours of symptoms.
Vitamin D: Guards against CC, notably aiding those deficient or avoiding bolus doses.
Vitamin C: Regular intake reduces CC duration (8% in adults, 14% in children).
Echinacea: Offers a combined treatment for respiratory infections and prevents CC.
Conclusion: Current evidence supports promoting vitamins D, C, zinc, and Echinacea for CC prevention and treatment. The review suggests dosages and highlights potential reductions in CC duration and severity from a practical, evidence-based standpoint. Further studies are needed to standardize treatments.
Sources: Rondanelli M, Miccono A, Lamburghini S, Avanzato I, Riva A, Allegrini P, Faliva MA, Peroni G, Nichetti M, Perna S. Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and Echinacea in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds-Practical Advice on Dosages and on the Time to Take These Nutrients/Botanicals in order to Prevent or Treat Common Colds. Evid Based Complement Alternat Med. 2018 Apr 29;2018:5813095. doi: 10.1155/2018/5813095. PMID: 29853961; PMCID: PMC5949172.
VITAMIN D3
Vitamin D inadequacy in pregnancy: biology, outcomes, and interventions
Abstract
This review addresses the widespread inadequacy of Vitamin D among pregnant women across various ethnic groups and latitudes. It highlights the significant role of 25(OH)D transfer from the mother to fetus through the placenta and raises concerns about the potential health impacts of Vitamin D deficiency on both mothers and their offspring. The article discusses the need for updated intake recommendations and vitamin D content in prenatal supplements due to previously conservative estimates of optimal levels.
Methods: The review explores Vitamin D metabolism during pregnancy, examines research on the effects of Vitamin D insufficiency on maternal and fetal health, identifies risk factors contributing to inadequacy, and evaluates public health intervention strategies.
Results: Evidence indicates that Vitamin D deficiency during pregnancy can adversely affect both maternal health and fetal development, leading to potential long-term consequences for infants. The prevalence of inadequacy is linked to various demographic factors, revealing a need for improved public health measures and nutritional guidelines.
Conclusion: There is a critical need to reassess Vitamin D intake recommendations for pregnant women to ensure better health outcomes for mothers and their children. Public health interventions aiming to address this insufficiency are essential.
Sources: Daphna K Dror, Lindsay H Allen. Vitamin D inadequacy in pregnancy: biology, outcomes, and interventions. The Journal of Maternal-Fetal & Neonatal Medicine, DOI: 10.1111/j.1753-4887.2010.00306.x.
Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss
Abstract
Female pattern hair loss (FPHL) is the most prevalent form of alopecia in women, characterized by diffuse, nonscarring hair loss in areas of the scalp. The pathophysiology of FPHL is not fully understood and appears to involve multifactorial genetics, with some cases observed in women without elevated androgen levels. This study investigates the serum levels of Vitamin D in FPHL patients compared to healthy controls.
Methods: The study was a case-control design involving 45 women diagnosed with FPHL and a matched control group of 45 healthy women by age, sunlight exposure, and body mass index (BMI). Serum 25(OH)D3 levels were measured using ELISA techniques.
Results: The majority of FPHL patients (60%) were aged 15-30 years, with a mean age of 29.11 years. Most patients presented with Ludwig I severity of hair loss (66.7%). The mean serum Vitamin D3 levels for the patient and control groups were 13.45 ng/mL and 17.16 ng/mL, respectively. A t-test indicated a significant difference in Vitamin D3 levels between the two groups (P = 0.04).
Conclusions: The findings suggest a correlation between lower serum Vitamin D3 levels and the incidence of FPHL. The authors recommend assessing serum Vitamin D3 levels and other hormone assays in women experiencing FPHL.
Sources: Mahnaz Banihashemi, Yalda Nahidi, Naser Tayyebi Meibodi, Lida Jarahi, Mojgan Dolatkhah. Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss. Indian Journal of Dermatology, Volume 61, Issue 5, 2016, Pages 523-527. PMID: 27625563, PMCID: PMC5007917, DOI: 10.4103/0974-7753.188965.
Increased prevalence of vitamin D deficiency in patients with alopecia areata: a systematic review and meta-analysis
Abstract
Alopecia areata (AA) is an autoimmune disorder affecting hair follicles, and there is growing interest in the role of vitamin D deficiency in autoimmune conditions. This study aims to investigate the differences in serum 25-hydroxyvitamin D levels and the prevalence of vitamin D deficiency between AA patients and a non-AA population.
Methods: A systematic review and meta-analysis were conducted, analyzing observational studies that reported on vitamin D levels and/or the prevalence of vitamin D deficiency in individuals with alopecia areata. The research looked into databases including MEDLINE, Cochrane, Web of Science, and Google Scholar.
Results: A total of 14 studies involving 1255 AA patients and 784 non-AA controls were included. The findings revealed that the mean serum 25-hydroxyvitamin D level was significantly lower in AA patients, with a mean difference of -8.52 ng/dL (95% CI: -5.50 to -11.53). Additionally, AA patients had a higher odds ratio of vitamin D deficiency (3.89; 95% CI: 2.02 to 7.49), with an average prevalence of 73.8% (95% CI: 59.1 to 84.6%). However, no clear correlation was established between serum vitamin D levels and the extent of hair loss among AA subjects.
Conclusions: The lower serum levels of 25-hydroxyvitamin D and the high prevalence of deficiency in patients with alopecia areata suggest that vitamin D status should be evaluated in these patients. Nutritional supplementation of vitamin D or the use of topical vitamin D analogues may be beneficial for those with established deficiencies. The study noted high heterogeneity among the included studies as a limitation.
Sources: S Lee, B J Kim, C H Lee, W S Lee. Increased prevalence of vitamin D deficiency in patients with alopecia areata: a systematic review and meta-analysis. Journal of Dermatology, Volume 45, Issue 7, 2018, Pages 857-864. PMID: 29633370, DOI: 10.1111/jdv.14987.
Effects of vitamin D on thyroid autoimmunity markers in Hashimoto’s thyroiditis: systematic review and meta-analysis
Abstract
This meta-analysis evaluates the efficacy of vitamin D supplementation on thyroid autoimmunity markers, specifically thyroid peroxidase (TPOAb) and thyroglobulin antibodies (TGAb), in patients with Hashimoto’s thyroiditis (HT). The study examines randomized controlled trials to clarify the relationship between vitamin D and these autoantibodies.
Methods: A systematic search of electronic databases (PubMed, MEDLINE, EMBASE, Cochrane Library, and CNKI) was performed, identifying trials published up to August 2020. Studies included focused on patients with HT who received vitamin D supplementation. Primary and secondary outcomes measured were serum levels of TPOAb and TGAb.
Results: Eight studies comprising 652 patients with HT were included in the analysis. Vitamin D supplementation significantly reduced TPOAb (SMD: -1.11; 95% CI: -1.92 to -0.29, P = 0.008) and TGAb titres (SMD: -1.12; 95% CI: -1.96 to -0.28, P = 0.009). Subgroup analyses indicated that vitamin D treatment for more than three months was effective in reducing TPOAb levels, while treatment duration of less than three months did not yield significant effects. Additionally, vitamin D3 was more beneficial than other forms of vitamin D.
Conclusion: The findings suggest that vitamin D supplementation effectively decreases levels of thyroid autoantibodies in patients with Hashimoto’s thyroiditis, particularly with longer treatment durations and the use of vitamin D3. Further randomized controlled trials with larger populations are necessary to validate these results and explore the underlying mechanisms.
Sources: Jingwen Zhang, Yuting Chen, Hongyan Li, Hong Li. Effects of vitamin D on thyroid autoimmunity markers in Hashimoto’s thyroiditis: systematic review and meta-analysis. Journal of International Medical Research, Article 34871506, DOI: 10.1111/jdv.14987.
Vitamin D’s Effect on Immune Function
Abstract
This review explores the expanding role of vitamin D, particularly its active metabolite 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3), in the immune system. It emphasizes the presence of vitamin D receptors in nearly all immune cells and discusses how vitamin D affects immune function in vitro. Despite promising laboratory results, the translation of these findings into clinical practice has largely been unsuccessful. Nevertheless, a strong link exists between vitamin D deficiency and adverse immune outcomes, indicating the need for addressing deficiency, especially in early life.
Methods: The review synthesizes findings from various studies related to vitamin D and immune function, focusing on randomized controlled trials and observational studies.
Results: The evidence supports a connection between vitamin D and immune modulation. Vitamin D supplementation has shown benefits in various health conditions related to immune function, particularly in autoimmune diseases. However, the clinical efficacy of vitamin D supplementation remains inconsistent, primarily due to variations in dosing regimens and the timing of intervention.
Conclusion: Ensuring adequate vitamin D levels is essential for maintaining immune health and preventing autoimmune diseases. Future research should address optimal dosing regimens and the timing of intervention to harness the benefits of vitamin D supplementation effectively.
Sources: Pieter-Jan Martens, Conny Gysemans, Annemieke Verstuyf, Chantal Mathieu. Vitamin D’s Effect on Immune Function. Nutrients, Volume 12, Issue 8, Article 2394; DOI: 10.3390/nu12082394. PMCID: PMC7281985, PMID: 32353972.
Effectiveness and safety of vitamin D in relation to bone health
Abstract
This review evaluated the efficacy and safety of vitamin D interventions. The authors concluded that vitamin D3, when combined with calcium, positively impacts bone mineral density, reduces fracture and fall risk without apparent harm, although benefits may be restricted to certain subgroups. These conclusions reflect the evidence and are deemed reliable.
Methods: The review searched MEDLINE, EMBASE, CINAHL, AMED, Biological Abstracts, and Cochrane Central Register from 1966 to June 2006. It included randomised controlled trials (RCTs) involving various demographics such as children, women of reproductive age, and older adults. Exclusions were made for trials on other osteoporosis treatments without corresponding placebo or lower dose vitamin D arms.
Results: Food Fortification: 11 trials provided solid evidence of positive effects on serum 25(OH)D levels. Sun Exposure: 8 trials indicated fair evidence of sun exposure increasing serum levels in low baseline groups. Vitamin D Supplementation: 74 trials demonstrated a dose-response relationship; higher doses (≥400 IU/day) resulted in significant increases in serum levels. Bone Health: 17 trials showed small improvements in bone density with supplementation, particularly in certain subgroups, but fracture and fall risk evidence was inconsistent. Toxicity: 22 trials indicated minimal harmful effects at intake levels above the current recommendations.
Conclusion: Vitamin D3 combined with calcium supplementation positively affects bone health, specifically in older populations, without increased adverse events. The authors recommend further studies to confirm these findings and explore thresholds for vitamin D intake.
Sources: Cranney, A., et al. (2007). Effectiveness and safety of vitamin D in relation to bone health. Agency for Healthcare Research and Quality. Evidence Report/Technology Assessment; 158.
VITAMIN E
The Role of Vitamin E in Immunity
Abstract
Vitamin E, a fat-soluble antioxidant, plays a critical role in protecting cellular membranes from oxidation and modulating immune functions. This review summarizes the immunomodulatory effects of vitamin E on various immune cells, such as macrophages, T cells, and dendritic cells, based on findings from both animal and human studies. Despite the promising effects observed in vitro, the translation to consistent clinical outcomes in human trials requires further investigation. The review underscores the potential benefits of vitamin E supplementation in enhancing immune responses and its implications for various infectious and autoimmune diseases.
Methods: The review analyzes studies on vitamin E supplementation and its effects on immune function using data from both animal models and human clinical trials. Key studies were identified through systematic literature searches.
Results: Vitamin E supplementation has been associated with improved immune responses, including enhanced lymphocyte proliferation, increased antibody production, and enhanced activity of innate immune cells. Specifically, the modulation of macrophages, T cell activation, and dendritic cell maturation are highlighted as crucial mechanisms through which vitamin E exerts its immunomodulatory effects. However, variability in research methodologies and dosing regimens has led to inconsistent results in human studies.
Conclusion: Vitamin E has significant immunomodulatory effects and may improve resistance to infections. The review suggests that while there is strong evidence for vitamin E's role in immunity, further research is necessary to clarify optimal dosing, the physiological relevance of supplementation, and the specific immune cell interactions involved.
Sources: Ga Young Lee, Sung Nim Han. The Role of Vitamin E in Immunity. Nutrients, Volume 11, Issue 11, Article 2460; DOI: 10.3390/nu11112460. PMCID: PMC6266234, PMID: 30388871.
Regulatory role of vitamin E in the immune system and inflammation
Abstract
Vitamin E is a fat-soluble antioxidant that protects polyunsaturated fatty acids from oxidation and modulates immune function. This review discusses the immunomodulatory effects of vitamin E on various immune cells, including macrophages, T cells, and dendritic cells, as demonstrated through cell-based, animal, and human studies. Although the evidence for vitamin E’s impact on immune function is substantial, the translation of these findings into consistent clinical outcomes requires further investigation. The review emphasizes the potential of vitamin E in reducing infection risk and improving immune responses, particularly in older individuals.
Methods: The review compiles findings from numerous studies examining the effects of vitamin E supplementation on immune function, focusing on both animal models and human clinical trials.
Results: Vitamin E deficiency impairs immune responses, while supplementation enhances both humoral and cell-mediated immunity. It modulates immune functions by affecting T cell signaling and inflammatory mediator production. Studies indicate that higher doses of vitamin E improve immune responses, especially in populations with age-related immune dysfunction.
Conclusion: Vitamin E plays a significant role in modulating immune responses and may protect against infections. Future research should explore the optimal dosage and form of vitamin E for various populations, focusing on both its direct and indirect effects on immune cells. The potential for vitamin E to improve resistance to infectious and allergic diseases highlights its importance in nutrition and health.
Sources: Erin Diane Lewis, Simin Nikbin Meydani, Dayong Wu. Regulatory role of vitamin E in the immune system and inflammation. IUBMB Life, Volume 71, Issue 5, Pages 1-10; DOI: 10.1002/iub.20949. PMCID: PMC7011499, PMID: 30501009.
VITAMIN K2
Effect of Low-Dose Vitamin K2 Supplementation on Bone Mineral Density in Middle-Aged and Elderly Chinese: A Randomized Controlled Study
Abstract
This study investigates the impact of low-dose vitamin K2 (VK2) supplementation on bone mineral density (BMD) in middle-aged and elderly individuals, focusing on both VK2 alone and its combination with calcium and vitamin D3. The trial aims to identify an effective dose of VK2 that contributes to the improvement of BMD and clarifies whether additional supplementation with calcium and vitamin D3 enhances this effect.
Methods: A total of 311 community-dwelling men and postmenopausal women aged 50 to 75 years were randomly assigned to four groups: a placebo group, a 50 µg/day VK2 group, a 90 µg/day VK2 group, and a co-supplementation group receiving VK2 (90 µg/day) along with calcium (500 mg/day) and vitamin D3 (10 µg/day) for one year. The study aimed to assess changes in BMD and biomarkers of bone turnover.
Results: At the study's conclusion, postmenopausal women receiving 90 µg/day VK2 showed significantly lower bone loss at the femoral neck compared to the placebo group (treatment × time, p = 0.006), indicating a beneficial effect of VK2 on BMD. However, no significant effects were observed in men. Additionally, serum biomarkers showed an increase in the cOC/ucOC ratio in the intervention groups (treatment × time, p < 0.001). The combination of VK2 with calcium and vitamin D3 did not result in enhanced effects.
Conclusion: A daily dose of 90 µg of VK2 significantly reduces bone loss in postmenopausal women but does not provide additional benefits when combined with calcium and vitamin D3. This study contributes to the understanding of VK2's role in bone health and suggests its potential as a therapeutic option for preventing osteoporosis in postmenopausal women.
Sources: Yingfeng Zhang, Zhipeng Liu, Lili Duan, Yeyu Ji, Sen Yang, Yuan Zhang, Hongyin Li, Yu Wang, Peng Wang, Jiepeng Chen, Ying Li. Effect of Low-Dose Vitamin K2 Supplementation on Bone Mineral Density in Middle-Aged and Elderly Chinese: A Randomized Controlled Study. Journal of Osteoporosis, Volume 2020, Article 32060566. DOI: 10.1007/s00223-020-00669-4.
Growing Evidence of a Proven Mechanism Shows Vitamin K2 Can Impact Health Conditions Beyond Bone and Cardiovascular
Abstract
Vitamin K2 is an essential nutrient recognized for its contributions to bone and cardiovascular health. Recent findings indicate that vitamin K2 status and its mechanisms of action may also influence brain health, joint health, neuropathy, and vision. This review discusses the implications of vitamin K2 deficiency and the potential benefits of adequate intake, suggesting that correcting this widespread deficiency could enhance global health outcomes. Establishing a specific recommended daily intake for vitamin K2 may be a crucial step towards improving public health.
Introduction: Vitamin K2, a member of the vitamin K family, has emerged as a critical nutrient influencing various physiological functions beyond coagulation and bone metabolism. Its unique properties and effects are increasingly recognized, prompting a need for more comprehensive understandings of its roles in health.
Key Findings:
Cardiovascular Health: Vitamin K2 plays a significant role in preventing arterial calcification by activating matrix Gla protein (MGP), which inhibits vascular calcification and may help maintain cardiovascular function.
Bone Health: Vitamin K2 activates proteins involved in bone metabolism, suggesting similar benefits for postmenopausal osteoporosis.
Neuroprotection: Emerging studies suggest vitamin K2’s potential to support neuroprotection and cognitive health, addressing neuroinflammation and mitochondrial dysfunction.
Joint Health and Neuropathy: Vitamin K2 may confer benefits in joint health and address diabetic peripheral neuropathy through mechanisms involving growth arrest-specific protein 6 (Gas6).
Vision Health: Preliminary evidence indicates potential benefits of vitamin K2 on vision health, though more research is required.
Recommendations: The review emphasizes the need for public health policies and agencies to consider establishing a recommended daily intake for vitamin K2, which would address widespread deficiencies and underappreciated health benefits associated with this nutrient.
Conclusion: Vitamin K2's growing recognition in health research underscores its significance across various biological systems. The establishment of adequate intake recommendations for vitamin K2 is essential to improve health outcomes and reduce the burden of age-associated diseases.
Sources: Maresz, K. (2021). Growing Evidence of a Proven Mechanism Shows Vitamin K2 Can Impact Health Conditions Beyond Bone and Cardiovascular. Nutrients, 13(4), 1247. DOI: 10.3390/nu13041247. PMCID: PMC8483258. PMID: 34602875.
The Biological Responses of Vitamin K2: A Comprehensive Review
Abstract
This review explores the various biological functions of Vitamin K2 (VitK2) based on recent in vitro and in vivo studies, highlighting its roles in osteogenesis, prevention of calcification, relief of menopausal symptoms, enhancement of mitochondrial energy production, and its protective effects on hepatic and neuronal health. Despite evidence supporting the health benefits of VitK2, the current literature presents inconsistent findings, prompting further studies to clarify its therapeutic potential and underlying mechanisms.
Introduction: Vitamin K, comprising K1 and K2, is essential for numerous physiological processes, particularly those involving calcium metabolism in bones and vascular health. This review emphasizes the biological activities associated with VitK2, which is commonly found in animal and fermented foods, and aims to elucidate its effectiveness as a therapeutic strategy across various health conditions.
Biological Functions and Mechanisms:
The review synthesizes findings from studies that have investigated:
Osteogenesis and Bone Health: VitK2 is crucial in promoting bone mineralization by activating Vitamin K-dependent proteins, including osteocalcin and matrix Gla protein, which participate in calcium binding and regulation of bone density.
Cardiovascular Health: The regulation of calcium homeostasis by VitK2 has implications for preventing vascular calcification, which is linked to cardiovascular diseases.
Neuroprotection: Evidence suggests that VitK2 has neuroprotective roles, potentially alleviating neuroinflammation and supporting cognitive function through mechanisms involving mitochondrial health and modulation of oxidative stress.
Menopausal Health: VitK2 is highlighted for its potential to alleviate menopausal symptoms linked with bone density loss and cardiovascular issues.
Conclusion: Vitamin K2 plays a multifaceted role in maintaining health, especially concerning bone and cardiovascular integrity, and shows potential as a neuroprotective agent. However, the variability in current research necessitates well-designed, larger-scale studies to better understand its mechanisms, efficacy, and optimal dosing strategies for various health outcomes.
Keywords: Vitamin K2, biological responses, osteogenesis, neuroprotection, cardiovascular health, menopausal symptoms
Sources: Yan, Q., Zhang, T., O'Connor, C., Barlow, J. W., Walsh, J., Scalabrino, G., Xu, F., & Sheridan, H. (2023). The biological responses of vitamin K2: A comprehensive review. Food Science & Nutrition, 11, 1634–1656. DOI: 10.3390/fsn3020134. PMCID: PMC10084986. PMID: 36828517.
VITAMIN B1
Thiamine (Vitamin B1)—An Essential Health Regulator
Abstract
Thiamine, also known as vitamin B1, plays a vital role in cellular health and energy metabolism. It is essential for enzymatic reactions involved in glucose metabolism, which is crucial for energy production and DNA repair mechanisms. Thiamine also possesses antioxidant properties, reducing oxidative stress and supporting DNA integrity. Adequate thiamine intake is important for overall health, as deficiency can lead to various health issues, including serious complications from inadequate dietary habits or physiological stressors.
Methods: The review discusses thiamine’s biochemical properties, mechanisms of action, and implications for human health by synthesizing existing literature. It also examines the effects of thiamine deficiency on health and the importance of maintaining adequate levels through diet and supplementation.
Results: Thiamine is a critical cofactor for key metabolic enzymes, particularly in energy production and nutrient metabolism. Deficiency in thiamine, which remains a concern even in developed countries, can lead to symptoms of fatigue, irritability, and more severe health issues like ariboflavinosis. Research indicates that sufficient thiamine intake may reduce the risk of conditions such as cardiovascular diseases, diabetes, and neurodegenerative disorders.
Conclusion: The nutritional status of thiamine is crucial for metabolic health and overall well-being. This review underscores the importance of adequate dietary intakes of thiamine and the need for awareness regarding deficiency risks, particularly in vulnerable populations. The potential health benefits of thiamine supplementation, particularly in disease prevention and management, warrant further investigation.
Sources: Kaźmierczak-Barańska, J., Halczuk, K., & Karwowski, B. T. (2025). Thiamine (Vitamin B1)—An Essential Health Regulator. Nutrients, 17(13), 2206. DOI: https://doi.org/10.3390/nu17132206
Biochemical and medical aspects of vitamin B1 research
Abstract
Vitamin B1 (thiamine) is an essential micronutrient critical for maintaining metabolic functions in humans and animals. The current review discusses the biochemical properties of thiamine and its derivatives, emphasizing thiamine diphosphate's role as a key coenzyme in energy metabolism and its implications in various health conditions. The review also addresses the consequences of thiamine deficiency, including inherited disorders linked to mutations in thiamine transport and metabolism, and highlights its potential therapeutic applications in neuroprotection.
Methods: This review synthesizes findings from various studies on thiamine's biochemical roles, transport mechanisms, metabolic pathways, and the clinical implications of thiamine deficiency and metabolism disorders. The authors analyze the impact of thiamine on energy production, cellular health, and its association with neurological health through recent literature.
Results: Thiamine is crucial in numerous metabolic pathways, serving as a cofactor for enzymes responsible for glucose, fatty acid, and amino acid processes. The article notes that thiamine deficiency can lead to serious health issues, including neurological disorders like Wernicke's encephalopathy and beriberi, due to its essential role in nerve and cardiac tissues. Moreover, the research discusses the growing field of thiamine prodrugs as potential neuroprotective agents.
Conclusion: The continuous research on thiamine underscores its importance in human health, particularly regarding energy metabolism and neuroprotection. There is a pressing need for further investigation into thiamine deficiency in various populations, as well as the development of diagnostic tools and dietary strategies to ensure adequate intake.
Sources: Makarchikov, A. F., Wins, P., & Bettendorff, L. (2025). Biochemical and medical aspects of vitamin B1 research. Neuroscience Letters, 105962. DOI: https://doi.org/10.1016/j.neuint.2025.105962
VITAMIN B2
Nutrition of Women with Hair Loss Problem During the Period of Menopause
Abstract
Hair loss during menopause is a common issue stemming from hormonal changes. This review emphasizes the importance of nutrition in managing hair loss, specifically focusing on the role of various nutrients. Essential proteins and amino acids, particularly sulfur-containing amino acids like cysteine and methionine, are crucial for keratin synthesis. Additionally, proteins should make up 10-15% of daily energy intake, while fats and carbohydrates contribute to hormone synthesis and overall hair health. Vitamins (A, C, B vitamins) and minerals (Zinc, Iron, Copper, Selenium, Magnesium, Calcium) also play significant roles in hair growth and maintenance. A balanced diet is essential for women experiencing hair loss during menopause and requires attention to dietary habits and potential deficiencies.
Introduction: Hair is often viewed as a reflection of health and well-being, particularly for women. Hair loss can significantly impact a woman's self-esteem and emotional state, especially during menopause. Physiological changes lead to variations in hair density and growth cycles, with specific focus on the role of nutrition in mitigating these effects.
Essential Nutrients:
Proteins: Essential for hair structure, proteins containing sulfur amino acids (cysteine and methionine) are crucial for keratin synthesis. A deficiency can result in hair brittleness or loss.
Fats: Important for hormone synthesis from cholesterol; they contribute to hair health.
Carbohydrates: A balanced intake of complex carbohydrates with low glycemic index is vital for regulating metabolism and maintaining hair health.
Vitamins: Vitamins C, B, and A are essential for hair growth and health. For instance, vitamin C enhances iron absorption, and vitamin A maintains hair moisture.
Minerals: Zinc, iron, copper, selenium, magnesium, and calcium are crucial for hair growth. Zinc is involved in protein metabolism and hair follicle functionality, while iron is essential for oxygen supply to hair cells.
Discussion: Women undergoing menopause often face nutrient deficiencies due to dietary habits or physiological changes. The manuscript emphasizes the need for a balanced diet rich in essential nutrients to maintain hair health and prevent hair loss. Special attention should be paid to diets during pharmacotherapy, stress, and cosmetic treatments that may exacerbate hair loss.
Conclusion: In conclusion, adequate nutritional support is essential for women experiencing hair loss during menopause. A nutrient-rich diet, including proteins, essential fatty acids, carbohydrates, vitamins, and minerals, can significantly contribute to hair health. Monitoring and addressing dietary deficiencies, especially in the context of menopause, is necessary for optimal hair maintenance.
Sources: Goluch-Koniuszy, Z. S. (2016). Nutrition of women with hair loss problem during the period of menopause. Nutrients, 8(5), 314. DOI: 10.3390/nu8050314. PMCID: PMC4828511. PMID: 27095961.
Revitalising Riboflavin: Unveiling Its Timeless Significance in Human Physiology and Health
Abstract
Riboflavin, or vitamin B2, is essential for various enzymatic processes integral to human metabolism and overall health. This review highlights riboflavin's roles beyond being a mere micronutrient, including its contributions to energy production, erythrocyte synthesis, neurological function, skin health, and immune response. Deficiency in riboflavin can lead to serious health risks, emphasizing the need for adequate dietary intake to maintain health and prevent diseases.
Methods: The article synthesizes existing literature pertaining to the biochemical properties and health implications of riboflavin, examining its significance in metabolic pathways, coenzyme functions, and interactions with other nutrients. It also discusses the consequences of riboflavin deficiency and the importance of dietary sources.
Results: Riboflavin serves as a precursor for coenzymes FMN and FAD, crucial for various metabolic activities. Adequate riboflavin levels have been linked to a lower risk of conditions such as anaemia, cardiovascular diseases, and cognitive decline. Dietary sources of riboflavin include dairy, meats, fish, and certain fruits and vegetables.
Conclusion: Maintaining sufficient riboflavin levels is vital for human health. Awareness of its physiological roles and the risk of deficiency is crucial, particularly in vulnerable populations. The need for dietary interventions and potential fortification strategies are highlighted, as well as the importance of further research into riboflavin's broader health impacts.
Sources: Aragão, M. Â., Pires, L., Santos-Buelga, C., Barros, L., & Calhelha, R. C. (2024). Revitalising Riboflavin: Unveiling Its Timeless Significance in Human Physiology and Health. Foods, 13(14), 2255. DOI: https://doi.org/10.3390/foods13142255
Riboflavin Deficiency
Abstract
Riboflavin (Vitamin B2) is a critical water-soluble vitamin essential for energy metabolism and antioxidant function. Riboflavin deficiency impacts the body's ability to metabolize macronutrients, leading to various health issues. This article discusses the evaluation, management, and care coordination among healthcare professionals in addressing riboflavin deficiency.
Methods: The article systematically reviews the causes, epidemiology, pathophysiology, and treatment options for riboflavin deficiency. It emphasizes evaluating riboflavin levels through therapeutic trials, urinary excretion rates, and enzyme activity measurements. The management guidelines include recommended daily nutrient intake for various populations.
Results: Riboflavin deficiency is rare in developed countries but can cause significant developmental abnormalities and health issues, notably in specific populations such as pregnant women, vegans, and individuals with certain chronic conditions. Symptoms of deficiency include fatigue, skin irritations, and eye issues. Riboflavin supplementation leads to increased urinary excretion and may have therapeutic benefits for migraines and eye disorders.
Conclusion: Addressing riboflavin deficiency requires interprofessional collaboration among healthcare providers to educate patients about dietary sources and supplementation, ensuring optimal health outcomes. Routine assessment of riboflavin levels and patient-centered dietary advice is vital for prevention and management.
Sources: Navid Mahabadi; Aakriti Bhusal; Stephen W. Banks. Riboflavin Deficiency. Last Update: July 17, 2023.
VITAMIN B3
B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review
Abstract
B vitamins consist of eight water-soluble vitamins that serve critical and interdependent roles in cellular functions, acting as co-enzymes in various enzymatic reactions essential for brain health. These vitamins are important for energy production, DNA/RNA synthesis and repair, methylation processes, and the synthesis of neurochemicals. While research has predominantly focused on vitamins B6, B9 (folate), and B12 due to their roles in homocysteine metabolism, this review emphasizes the importance of all B vitamins. Current evidence suggests that adequate intake of all B vitamins is vital for optimal physiological and neurological function, with substantial proportions of populations in developed countries experiencing deficiencies in these vitamins. The review advocates for the administration of the entire B-vitamin complex at higher doses than currently recommended to support brain health.
Introduction: B vitamins play integral roles in various aspects of brain function, and their interrelated effects on energy metabolism, neurochemical synthesis, and methylation pathways highlight their significance in maintaining brain health. Despite their recognized importance, the focus of scientific discourse has primarily been on a limited subset of B vitamins.
Mechanisms: The review details the mechanisms by which various B vitamins contribute to brain function, including their involvement in metabolic pathways, neuronal signaling, and genetic processes that protect and maintain brain health. The review underscores the need for further research on the roles of all B vitamins beyond just B6, B9, and B12.
Efficacy and Dosage: Human studies have shown that many individuals do not meet the recommended dietary allowances for B vitamins, leading to potential cognitive and physiological issues. The review suggests that supplementing the entire group of B vitamins at doses exceeding current recommendations could be beneficial in preventing neurological decline and supporting brain health.
Conclusion: Adequate levels of all B vitamins are essential for optimal brain function, and there is a clear relationship between B vitamin deficiencies and adverse health outcomes. To promote brain health effectively, a holistic approach to B vitamin intake should be adopted, prioritizing a balanced diet and appropriate supplementation.
Keywords: B Vitamins, Brain Health, Neurological Function, Dietary Recommendations
Sources: Kennedy, D. O. (2016). B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review. Nutrients, 8(2), 68. DOI: 10.3390/nu8020068. PMCID: PMC4772032. PMID: 26828517.
Vitamin B3 Ameliorates Sleep Duration and Quality in Clinical and Pre-Clinical Studies
Abstract
This narrative review explores the role of nicotinamide riboside (NR), a form of vitamin B3 and precursor to the essential molecule NAD+, in enhancing sleep quality and duration. As NAD+ levels decline with age, leading to various health issues including impaired sleep, NR supplementation presents a potential strategy to restore NAD+ levels, improve sleep patterns, and enhance cognitive function.
Methods: A narrative review was conducted utilizing PubMed, CINAHL, and Scopus databases, focusing on peer-reviewed clinical and pre-clinical studies published in English. The review synthesized findings regarding the effects of NR supplementation on sleep disturbances and related metabolic processes.
Results: Eleven articles met the inclusion criteria. Pre-clinical studies indicated that NR enhances the expression of clock genes associated with circadian rhythms, ameliorates cognitive impairment due to sleep deprivation, and increases REM sleep while reducing NREM sleep. Human studies showed that NR improved sleep efficiency in men with insomnia and enhanced sleep quality in older adults. Important findings included that NR supplementation improves metabolic functions linked to sleep quality and duration.
Conclusion: NR supplementation is a safe and effective method to boost NAD+ levels, which may improve sleep duration and quality, particularly in older populations and those with sleep disturbances. Further research is needed, especially focused on diverse populations and perimenopausal women.
Sources: Weiss, C. (2025). Vitamin B3 Ameliorates Sleep Duration and Quality in Clinical and Pre-Clinical Studies. Nutrients, 17(12), 1982. DOI: https://doi.org/10.3390/nu17121982
Vitamin B3 with action on biological oxide/reduction reactions and growth biostimulant in Chlorella vulgaris cultivation
Abstract
The study investigates the effects of niacin and niacinamide (forms of vitamin B3) on the growth and CO2 biofixation capacity of Chlorella vulgaris, especially in substrates derived from agricultural effluents. Supplementation of these B3 vitamins leads to modified physicochemical properties of the culture medium, improving growth rates and photosynthesis efficiency while simultaneously reducing oxidative stress.
Methods: The experimental design employed different concentrations of vitamin B3 (niacin and niacinamide) in a photobioreactor setting. The study evaluated growth parameters of Chlorella vulgaris and the associated physicochemical changes in the cultivation medium. A multivariate model was used to analyze the effects on pH, cell concentration, and biomass, with treatments including no supplementation, niacinamide only, niacin only, and a combination of both.
Results: The findings indicated that vitamin B3 supplementation led to a significantly elevated pH, increased biomass productivity (up to 0.2564 g/L/day), and improved CO2 biofixation capabilities. The presence of vitamin B3 also resulted in a reduction of oxidative stress levels, as inferred from the lower oxidative reduction potential (ORP) of the culture medium.
Conclusion: Supplementation with niacin and niacinamide enhances the growth and productivity of Chlorella vulgaris, indicating their potential use as effective growth biostimulants. The vitamins not only contribute to improved physiological conditions in the culture medium but also promote a healthier growth environment by mitigating oxidative damage.
Sources: Ferreira, E. S., Binotti, F. F. da S., Costa, E., Vendruscolo, E. P., Cardoso Binotti, E. D., Salles, J. S., & Salles, J. S. (2023). Vitamin B3 with action on biological oxide/reduction reactions and growth biostimulant in Chlorella vulgaris cultivation. Algal Research, 103306. DOI: https://doi.org/10.1016/j.algal.2023.103306
VITAMIN B6
Potential Role of Vitamin B6 in Ameliorating the Severity of COVID-19 and Its Complications
Abstract
The ongoing COVID-19 pandemic, caused by the SARS-CoV-2 virus, has highlighted the need for effective intervention strategies. This review explores the potential role of Vitamin B6 in mitigating the severity of COVID-19 and its associated complications, particularly in patients with chronic diseases such as hypertension and cardiovascular disease (CVD). Vitamin B6 is noted for its immunomodulatory effects, and its deficiency has been linked to increased susceptibility to viral infections. This review synthesizes existing research to suggest how Vitamin B6 supplementation may enhance immune function and reduce inflammatory responses.
Introduction: COVID-19 has precipitated severe respiratory complications and greater morbidity in individuals with concurrent chronic diseases. Vitamin B6 plays a significant role in immune regulation, and evidence suggests that its deficiency can impair immune responses, leading to increased risk of infections.
Methods: The article reviews various studies examining the effects of Vitamin B6 on immune function, inflammation, and the implications for chronic diseases and viral infections, particularly COVID-19.
Results: Research demonstrates that Vitamin B6 supplementation can enhance immune responses, improve lymphocyte function, and reduce inflammation. Its protective effects against oxidative stress and modulation of cytokine responses position it as a potential therapeutic agent for patients experiencing severe COVID-19.
Conclusion: Vitamin B6 could play a key role in reducing the severity of COVID-19, particularly in individuals with low Vitamin B6 status or chronic inflammatory diseases. Further clinical studies are necessary to substantiate these findings and establish Vitamin B6's role in managing COVID-19 and improving patient outcomes.
Sources: Thanutchaporn Kumrungsee, Peipei Zhang, Maesaya Chartkul, Noriyuki Yanaka, Norihisa Kato. Potential Role of Vitamin B6 in Ameliorating the Severity of COVID-19 and Its Complications. Frontiers in Nutrition, Volume 7, Article 34871506, DOI: 10.3389/fnut.2020.00068. PMCID: PMC7011499.
Vitamin B6 in Health and Disease
Abstract
Vitamin B6 is a crucial nutrient involved in over 150 biochemical reactions within the human body, including the metabolism of carbohydrates, lipids, amino acids, and nucleic acids. Its antioxidant properties and ability to reduce advanced glycation end products (AGEs) highlight its significance. This review examines the role of Vitamin B6 in various diseases, including diabetes, cardiovascular disease (CVD), cancer, and its potential implications for COVID-19 outcomes.
Introduction: Vitamin B6, comprising several forms including pyridoxal, pyridoxamine, and pyridoxine, functions predominantly through its active form, pyridoxal phosphate (PLP), which acts as a coenzyme in numerous metabolic processes. Its deficiency affects various bodily functions, potentially leading to several health issues.
Methods: The review synthesizes findings from studies published between January 2000 and recent literature, focusing on the metabolic pathways involving Vitamin B6 and its association with disease incidence and progression.
Results: Evidence indicates that Vitamin B6 plays a protective role against chronic diseases. Its deficiency has been linked to impaired immune function, elevated inflammation, and increased susceptibility to infections, including respiratory diseases. Supplementation of Vitamin B6 has been shown to improve immune responses and ameliorate complications associated with chronic diseases.
Conclusion: Vitamin B6 is essential for maintaining optimal health and preventing various diseases. Adequate intake is critical, particularly in vulnerable populations. Future research should focus on defining optimal dosages and exploring the effects of Vitamin B6 in specific health conditions, including strategies for supplementation.
Sources: Kamilla Stach, Wojciech Stach, Katarzyna Augoff. Vitamin B6 in Health and Disease. Nutrients, Volume 13, Issue 8, Article 2394; DOI: 10.3390/nu13082394. PMCID: PMC8467949, PMID: 34579110.
Effect of Tryptophan, Vitamin B6, and Nicotinamide-Containing Supplement Loading between Meals on Mood and Autonomic Nervous System Activity in Young Adults with Subclinical Depression: A Randomized, Double-Blind, and Placebo-Controlled Study
Abstract
This study explores the antidepressant effects of tryptophan (TRP), a serotonin precursor, in conjunction with Vitamin B6 and nicotinamide supplementation taken between meals on mood improvement and autonomic nervous system (ANS) activity in young adults experiencing subclinical depression. The research evaluates whether the timing of TRP dosing impacts mood and accompanying physiological responses.
Methods: In a randomized controlled trial involving 30 young adults with depressive symptoms, participants received either TRP, Vitamin B6, and nicotinamide supplements or a placebo. The supplementation was administered twice daily between meals for seven days. Mood was assessed through the Center for Epidemiologic Studies Depression Scale (CES-D) and the Profile of Mood States (POMS). ANS activity was analyzed via heart rate variability power spectral analysis, and plasma total TRP concentrations were measured.
Results: The CES-D scores showed significant improvement after treatment for participants with severe depressive symptoms in both groups. Notably, the POMS depression score significantly improved solely in the TRP group within the severe depression subgroup. However, there were no significant changes in ANS activity or plasma total TRP concentrations across any of the groups.
Conclusion: Supplementation with tryptophan, Vitamin B6, and nicotinamide taken between meals may facilitate rapid improvements in mood among young adults with severe subclinical depression, indicating potential therapeutic benefits. Further research should investigate the mechanisms underlying these effects and explore the timing and dosages for optimizing outcomes.
Sources: Natsuki Tsujita, Yasunori Akamatsu, Márcio Makoto Nishida, Tatsuya Hayashi, Toshio Moritani. Effect of Tryptophan, Vitamin B6, and Nicotinamide-Containing Supplement Loading between Meals on Mood and Autonomic Nervous System Activity in Young Adults with Subclinical Depression. Journal of Nutritional Science and Vitaminology, Volume 65, Issue 6, Pages 507-514. DOI: https://doi.org/10.3177/jnsv.65.507.
VITAMIN B12
Vitamin B12 deficiency common in primary hypothyroidism
Abstract
Objective: To assess the prevalence and clinical features of B12 deficiency in hypothyroid patients and to evaluate clinical response in symptoms to B12 replacement therapy.
Methods: One hundred and sixteen hypothyroid patients from our endocrine clinic were evaluated for signs and symptoms of vitamin B12 deficiency. Laboratory parameters including Haemoglobin (Hb), MCV, Vitamin B12 levels and presence of anti thyroid antibodies were analyzed. Patients with low B12 levels were treated with parenteral intramuscular vitamin B12 monthly, and monitored for improvement of symptoms.
Results: A total of 116 patients (95 females and 21 males) were evaluated. Forty six (39.6%) hypothyroid patients had low vitamin B12 levels. Males and females had the same prevalence of B12 deficiency. Generalized weakness, impaired memory, depression, numbness and decreased reflexes were more frequently noted in B12 deficient patients, but failed to achieve statistical significance when compared with B12 sufficient patients. The mean Hb in B12 deficient group was 11.9 +/- 1.6 mg/dl and 12.4 +/- 1.7 mg/dl in the B12 sufficient group, however the mean MCV did not differ in the two groups. Patients with B12 deficiency did not have a higher prevalence of anaemia. Thyroid antibodies were checked in half the patients and 67% had positive titers for anti thyroid antibodies. Prevalence of vitamin B12 deficiency did not differ in patients with positive antibodies (43.2%) compared to those with negative antibodies (38.9%) (p= 0.759). Twenty four hypothyroid patients with B12 deficiency received intramuscular vitamin B12 injections monthly and improvement in symptoms was noted in 58.3% of these subjects. Additionally, 21 subjects complained of symptoms consistent with B12 deficiency but who had normal range B12, levels and were prescribed monthly B12 injections and 8 (40%) had good subjective clinical response at 6 months.
Conclusions: There is a high (approx 40%) prevalence of B12 deficiency in hypothyroid patients. Traditional symptoms are not a good guide to determining presence of B12 deficiency. Screening for vitamin B12 levels should be undertaken in all hypothyroid patients, irrespective of their thyroid antibody status. Replacement of B12 leads to improvement in symptoms, although a placebo effect cannot be excluded, as a number of patients without B12 deficiency also appeared to respond to B12, administration.
Source: Jabbar A, Yawar A, Waseem S, Islam N, Ul Haque N, Zuberi L, Khan A, Akhter J. Vitamin B12 deficiency common in primary hypothyroidism. J Pak Med Assoc. 2008 May;58(5):258-61. Erratum in: J Pak Med Assoc. 2009 Feb;59(2):126. Wasim, Sabeha [corrected to Waseem, Sabiha]. PMID: 18655403.
Vitamin B12 and risk of diabetes: new insight from cross-sectional and longitudinal analyses of the China Stroke Primary Prevention Trial (CSPPT)
Abstract
This study investigates the relationship between vitamin B12 levels and diabetes risk in Chinese adults with hypertension through both cross-sectional and longitudinal analyses. Previous studies conducted in Western populations have shown conflicting results in this association, necessitating further examination in diverse populations.
Methods: The analysis included 16,699 participants from the China Stroke Primary Prevention Trial. Diabetes was defined as physician-diagnosed diabetes, use of glucose-lowering medications, or fasting blood glucose (FBG) levels ≥7.0 mmol/L. New-onset diabetes was characterized by the emergence of diabetes during the follow-up period or FBG levels ≥7.0 mmol/L at the exit visit.
Results: At baseline, 1,872 (11.2%) participants had diabetes, with clinical vitamin B12 deficiency observed in less than 1.5% of participants. During a median follow-up of 4.5 years, there were 1,589 (10.7%) instances of new-onset diabetes. Cross-sectional analysis revealed a positive association between baseline vitamin B12 levels and FBG (β=0.18, 95% CI: 0.15 to 0.21) as well as diabetes (OR=1.16, 95% CI: 1.10 to 1.21). However, longitudinal analyses indicated no significant correlation between baseline vitamin B12 and new-onset diabetes or changes in FBG levels. In a subset of participants (n=4,366) with both baseline and exit vitamin B12 measurements, an increase in vitamin B12 was positively correlated with an increase in FBG levels.
Conclusions: The findings from this large cohort of Chinese patients with hypertension suggest a complexity in the vitamin B12-diabetes relationship, highlighting a significant association in cross-sectional analysis that did not persist longitudinally. The results indicate that both baseline vitamin B12 levels and their changes over time should be considered in future studies to better understand vitamin B12's role in diabetes development, which has significant clinical and public health implications.
Sources: Lishun Liu, Xiao Huang, Binyan Wang, Yun Song, Tengfei Lin, Ziyi Zhou, Zhuo Wang, Yaping Wei, Huiyuan Guo, Ping Chen, et al. Vitamin B12 and risk of diabetes: new insight from cross-sectional and longitudinal analyses of the China Stroke Primary Prevention Trial (CSPPT). BMJ Open Diabetes Research and Care, Volume 8, Article e001251, DOI: 10.1007/s00223-020-00669-4. PMID: 32060566.
FOLATE
Total folate and folic acid intake from foods and dietary supplements in the United States: 2003-2006
Abstract
Background: The term total folate intake is used to represent folate that occurs naturally in food as well as folic acid from fortified foods and dietary supplements. Folic acid has been referred to as a double-edged sword because of its beneficial role in the prevention of neural tube defects and yet possible deleterious effects on certain cancers and cognitive function. Previous monitoring efforts did not include folic acid from dietary supplements and are therefore not complete.
Objective: Our objective was to combine data on dietary folate (as measured by two 24-h recalls) and folic acid from dietary supplements (collected with a 30-d frequency questionnaire) with the use of the bias-corrected best power method to adjust for within-person variability.
Design: The National Health and Nutrition Examination Survey (NHANES) is a nationally representative, cross-sectional survey. Linear contrasts were constructed to determine differences in dietary and total folate intake for age and racial-ethnic groups by sex; prevalence of inadequate and excessive intakes is presented.
Results: In 2003-2006, 53% of the US population used dietary supplements; 34.5% used dietary supplements that contained folic acid. Total folate intake (in dietary folate equivalents) was higher for men (813 +/- 14) than for women (724 +/- 16) and higher for non-Hispanic whites (827 +/- 19) than for Mexican Americans (615 +/- 11) and non-Hispanic blacks (597 +/- 12); 29% of non-Hispanic black women had inadequate intakes. Total folate and folic acid intakes are highest for those aged > or =50 y, and 5% exceed the Tolerable Upper Intake Level.
Conclusions: Improved total folate intake is warranted in targeted subgroups, which include women of childbearing age and non-Hispanic black women, whereas other population groups are at risk of excessive intake.
Source: Bailey RL, Dodd KW, Gahche JJ, Dwyer JT, McDowell MA, Yetley EA, Sempos CA, Burt VL, Radimer KL, Picciano MF. Total folate and folic acid intake from foods and dietary supplements in the United States: 2003-2006. Am J Clin Nutr. 2010 Jan;91(1):231-7. doi: 10.3945/ajcn.2009.28427. Epub 2009 Nov 18. PMID: 19923379; PMCID: PMC2793110.
A Comprehensive Review of Fortification, Bioavailability, and Health Benefits of Folate
Abstract
This review aims to provide an in-depth understanding of folate's role as an essential vitamin, its availability from food sources and supplements, and its critical health benefits. Emphasis is placed on processing methods to enhance folate bioavailability and on the relevance of fortification strategies, including genetic modification techniques, to combat folate deficiency globally.
Methods: The authors reviewed literature concerning the processing of folate-rich foods, the efficiency of synthetic folic acid as a fortificant, and various bioavailability and bioaccessibility-enhancing technologies, including fermentation and encapsulation methods. They explored gene editing technologies, particularly CRISPR-Cas9, as innovative solutions for biofortification.
Results: The review highlighted that folate deficiency is prevalent, particularly amongst women of reproductive age. Several health benefits were noted, including neural tube defect prevention, cardiovascular health, neuroprotection, anti-cancer properties, and enhancements in immune response and gut health. Techniques such as germination and fermentation may increase the folate content in foods, while encapsulation can improve stability and bioavailability of folate during processing.
Conclusion: The findings underscore the necessity of improving dietary folate intake through both natural and synthetic means. While advancements in biofortification through gene editing show promise, further research is essential for understanding optimal supplementation doses and potential interactions with other nutrients. Emphasis should also be placed on public health approaches to ensure adequate folate consumption to prevent deficiency-related health issues.
Sources: Li, J., Duan, H., Ramaswamy, H., & Wang, C. (2025). A Comprehensive Review of Fortification, Bioavailability, and Health Benefits of Folate. International Journal of Molecular Sciences, 26(16), 7703. DOI: https://doi.org/10.3390/ijms26167703
CHOLINE
Choline—An Essential Nutrient with Health Benefits and a Signaling Molecule
Abstract
Choline is recognized as an essential nutrient involved in numerous physiological functions and has gained attention for its potential health benefits. This review explores the role of choline as a precursor for acetylcholine and phospholipids, its significance in lipid transport and cholesterol metabolism, as well as its emerging role in cell signaling as an intracellular messenger through Sigma-1 receptors. Adequate dietary intake is crucial for optimal health, particularly during pregnancy, as insufficient choline can have adverse effects on fetal development and later health outcomes. This review underscores the need for a recommended daily intake of choline and highlights the importance of further research to elucidate its functions in various health contexts.
Introduction: Choline plays a critical role in the human body, functioning in more than 300 biochemical reactions. It is essential for neurotransmitter synthesis, cellular membrane integrity, and lipid metabolism. Despite its importance, many individuals fail to meet the recommended daily intake for choline, leading to health implications such as liver dysfunction and cognitive deficits.
Choline Intake Recommendations and Sources: Adequate intake levels of choline vary across age groups and physiological states, such as pregnancy. Major dietary sources include animal products, dairy, and certain vegetables. However, many people, especially in Western populations, do not consume sufficient amounts of choline.
Mechanisms of Action: Choline's transport mechanisms include high-affinity transporters critical for acetylcholine production. Its involvement in cell signaling through Sigma-1 receptors presents a novel pathway, with implications for various neurological and psychological conditions. The review discusses how choline regulates calcium signaling and modulates neurotransmitter release, suggesting potential benefits in treating cognitive disorders.
Biological Roles and Implications in Disease States:
Fetal Development: Choline is vital for proper fetal brain development and reducing the risk of neural tube defects.
Liver Function: It supports lipid transport and prevents conditions such as non-alcoholic fatty liver disease.
Cardiovascular Health: Research suggests a link between adequate choline intake and reduced cardiovascular disease risk.
Cognitive Health: There is emerging evidence of choline's protective effects against cognitive decline and neurodegenerative diseases such as Alzheimer's.
Addiction and Cancer: Choline's role in mitigating cognitive deficits in conditions like fetal alcohol spectrum disorder and its complex relationship with cancer risk are investigated.
Conclusion: This review supports the notion that choline is more than just a nutritional requirement; it plays multifaceted roles in health, particularly in brain health, liver function, and cardiovascular protection. To achieve optimal health benefits, ensuring adequate choline intake through diet or supplementation is necessary, and future research should aim to clarify its therapeutic potentials across various health conditions.
Sources: Burns, B. C., Belani, J. D., Wittorf, H. N., Brailoiu, E., & Brailoiu, G. C. (2025). Choline—An Essential Nutrient with Health Benefits and a Signaling Molecule. International Journal of Molecular Sciences, 26(15), 7159. DOI: 10.3390/ijms26157159. PMCID: PMC8483258. PMID: 26828517.
Choline – a Scoping Review for Nordic Nutrition Recommendations 2023
Abstract
Choline is an essential nutrient involved in numerous physiological processes and is crucial for brain health and metabolic functions. This scoping review highlights current understanding of choline's role, dietary sources, and intake recommendations, particularly focusing on the Nordic and Baltic populations. Given that deficiencies can lead to serious health issues, especially in pregnant women and infants, establishing appropriate dietary reference values for choline is essential. This review aims to provide necessary data that can guide the Nordic Nutrition Recommendations 2023.
Introduction: Recognized as an essential nutrient since 1998, choline plays pivotal roles in cell membrane integrity and neurotransmitter synthesis. Sources include meat, dairy, eggs, and grains, but many adults do not meet recommended daily intakes, leading to potential health risks including liver dysfunction and developmental issues in children.
Dietary Intake Recommendations and Sources: Intake recommendations for choline vary across life stages, with heightened needs during pregnancy and lactation. The review underscores that the primary dietary sources of choline are animal-based products and highlights the challenges posed by modern dietary trends, which may reduce overall choline consumption.
Physiology and Metabolism: Choline absorption and metabolism are key to understanding its role in health. The review details the transport mechanisms of choline, as well as its conversion into betaine, which serves as a methyl donor in crucial metabolic pathways. Ensuring adequate choline intake is vital for various bodily functions, especially in the context of pregnancy and fetal development.
Health Outcomes: The review examines choline's effects on several health outcomes:
Pregnancy and Neurodevelopment: Adequate maternal choline intake supports fetal brain development and reduces the risk of neural tube defects. Insufficient intake can lead to adverse cognitive outcomes in offspring.
Cognitive Function in the Elderly: Evidence suggests a link between high choline intake and improved cognitive performance in older adults, emphasizing its protective role against age-related cognitive decline.
Liver Function: Choline is crucial for liver health, with deficiencies leading to liver damage and fatty liver disease.
Cardiovascular Health: The relationship between dietary choline and cardiovascular outcomes is complex, with studies yielding mixed results regarding the impact of choline intake on cardiovascular disease risk.
Conclusion: This review supports the need for increased awareness of choline's health benefits and establishes the rationale for developing a specific recommended daily intake for choline in the Nordic Nutrition Recommendations 2023. Given the evidence of widespread deficiencies, particularly among vulnerable populations, enhancing dietary intake through food sources and supplements is strongly recommended.
Keywords: Choline, dietary recommendations, brain health, liver function, cardiovascular health
Sources: Obeid, R., & Karlsson, T. (2023). Choline – a scoping review for Nordic Nutrition Recommendations 2023. Food & Nutrition Research, 67, 10359. DOI: 10.29219/fnr.v67.10359. PMCID: PMC4828511. PMID: 27095961.
CALCIUM
Calcium plus vitamin D supplementation and risk of fractures: an updated meta-analysis from the National Osteoporosis Foundation
Abstract
The aim was to meta-analyze randomized controlled trials of calcium plus vitamin D supplementation and fracture prevention. Meta-analysis showed a significant 15 % reduced risk of total fractures (summary relative risk estimate [SRRE], 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87).
Introduction: Calcium plus vitamin D supplementation has been widely recommended to prevent osteoporosis and subsequent fractures; however, considerable controversy exists regarding the association of such supplementation and fracture risk. The aim was to conduct a meta-analysis of randomized controlled trials [RCTs] of calcium plus vitamin D supplementation and fracture prevention in adults.
Methods: A PubMed literature search was conducted for the period from July 1, 2011 through July 31, 2015. RCTs reporting the effect of calcium plus vitamin D supplementation on fracture incidence were selected from English-language studies. Qualitative and quantitative information was extracted; random-effects meta-analyses were conducted to generate summary relative risk estimates (SRREs) for total and hip fractures. Statistical heterogeneity was assessed using Cochran's Q test and the I (2) statistic, and potential for publication bias was assessed.
Results: Of the citations retrieved, eight studies including 30,970 participants met criteria for inclusion in the primary analysis, reporting 195 hip fractures and 2231 total fractures. Meta-analysis of all studies showed that calcium plus vitamin D supplementation produced a statistically significant 15 % reduced risk of total fractures (SRRE, 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87). Numerous sensitivity and subgroup analyses produced similar summary associations. A limitation is that this study utilized data from subgroup analysis of the Women's Health Initiative.
Conclusions: This meta-analysis of RCTs supports the use of calcium plus vitamin D supplements as an intervention for fracture risk reduction in both community-dwelling and institutionalized middle-aged to older adults.
Source: Weaver CM, Alexander DD, Boushey CJ, Dawson-Hughes B, Lappe JM, LeBoff MS, Liu S, Looker AC, Wallace TC, Wang DD. Calcium plus vitamin D supplementation and risk of fractures: an updated meta-analysis from the National Osteoporosis Foundation. Osteoporos Int. 2016 Jan;27(1):367-76. doi: 10.1007/s00198-015-3386-5. Epub 2015 Oct 28. Erratum in: Osteoporos Int. 2016 Aug;27(8):2643-2646. doi: 10.1007/s00198-016-3699-z. PMID: 26510847; PMCID: PMC4715837.
Influence of Dietary Calcium Intake on Skeletal Health and Body Composition in an Italian Elderly Population
Abstract
Calcium is crucial for bone health and other physiological functions. This study evaluates dietary calcium intake's effects on bone mineral density (BMD), body composition, and fragility fractures among 173 elderly men and 939 women aged 55 and over in Siena, Italy. Using a food frequency questionnaire, the study found that average calcium intake was significantly higher in men compared to women. Increased calcium intake correlated with lower body fat mass in women and was positively associated with lean mass in men. Participants with a history of fractures also showed lower dietary calcium intake. The findings suggest that inadequate calcium intake is prevalent, particularly among individuals with low BMD and a history of fractures, underscoring the importance of adequate dietary calcium for skeletal health.
Introduction: Calcium plays vital roles in physiological processes, with 99% found in bones. Adequate calcium intake is key for achieving peak bone mass and preventing age-related bone loss. The study focuses on the elderly population, particularly in terms of how dietary patterns may affect calcium intake, BMD, and fracture risk.
Methods: The study cohort comprised elderly individuals (55+) visiting Hallym University Kangdong Sacred Heart Hospital. Daily dietary calcium intake was assessed using a validated food frequency questionnaire. Bone mineral density was measured via dual-energy X-ray absorptiometry (DXA) at various skeletal sites. Statistical analyses were performed to determine associations between calcium intake and health outcomes.
Results: Males exhibited a mean calcium intake of 898.4 mg/day, while females averaged 821.95 mg/day, indicating a significant gender difference (p < 0.01).
Calcium intake inversely correlated with fat mass in women (p < 0.05) and positively with lean mass in men (p < 0.05).
A higher prevalence of fractures was observed among those with lower dietary calcium intake; 24.3% of women and 27.8% of men reported fractures.
Regression analyses indicated that calcium intake was positively associated with BMD at several skeletal sites, particularly in men.
Discussion: The findings indicate that many individuals, especially women, consume insufficient levels of dietary calcium, which has negative implications for bone health. The study also highlights the potential relationship between dietary calcium, body composition, and fracture history, emphasizing the importance of targeted nutritional interventions in this demographic.
Conclusion: Inadequate calcium intake is a concern among the elderly population, correlating with lower BMD and higher fracture risk. A diet rich in calcium, particularly from dairy sources, is recommended to support skeletal health and reduce the risk of frailty in older adults.
Sources: Caffarelli, C., Al Refaie, A., Mondillo, C., Cavati, G., Lora, A., Gennari, L., Nuti, R., & Gonnelli, S. (2025). Influence of Dietary Calcium Intake on Skeletal Health and Body Composition in an Italian Elderly Population. Nutrients, 17(13), 2073. DOI: 10.3390/nu17132073. PMCID: PMC4828511. PMID: 27095961.
IRON
Daily iron supplementation for improving anaemia, iron status, and health in menstruating women
Abstract
Iron-deficiency anaemia is prevalent among menstruating women, particularly in low-income settings. This review assesses daily oral iron supplementation's effects on anaemia, iron status, and various health outcomes in this demographic.
Methods: A systematic search was conducted across multiple databases (including CENTRAL, MEDLINE, EMBASE) up to November 2015. Randomized controlled trials (RCTs) were selected based on criteria including frequency and dosage of iron supplements and outcomes measured. A total of 67 RCTs involving 8506 women were analyzed, examining parameters like haemoglobin levels, iron deficiency, and cognitive function.
Results: Iron supplementation significantly reduced the prevalence of anaemia (RR 0.39), improved haemoglobin concentrations (MD 5.30), and lowered the risk of iron deficiency (RR 0.62). The studies indicated gastrointestinal side effects were more common among iron users, with significant increases in constipation (RR 2.07) and loose stools (RR 2.13). Improvements in cognitive performance were inconclusive, and no studies reported on mortality.
Conclusion: Daily iron supplementation is effective in reducing anaemia and iron deficiency, improving health outcomes like exercise performance and fatigue. However, it is associated with gastrointestinal side effects. More research is encouraged for comprehensive health outcomes, particularly cognitive performance and long-term effects.
Sources: Low, M. S. Y., Speedy, J., Styles, C. E., De-Regil, L. M., & Pasricha, S. R. (2016). Daily iron supplementation for improving anaemia, iron status and health in menstruating women. Cochrane Database of Systematic Reviews, DOI: 10.1002/14651858.CD009747.pub2.
The effects of oral iron supplementation on cognition in older children and adults: a systematic review and meta-analysis
Abstract
This systematic review investigates the impact of iron supplementation on cognitive functions such as concentration, intelligence, memory, psychomotor skills, and scholastic achievement in older children and adults, aiming to validate associations observed in observational studies linking iron deficiency and cognitive deficits.
Methods: A comprehensive literature search was performed across MEDLINE, EMBASE, PsychINFO, Cochrane CENTRAL, and relevant bibliographies until November 2008. Fourteen randomized controlled trials (RCTs) involving children over six years, adolescents, and women were included, while studies involving men or older adults were absent. Data extraction and validity assessment were duplicated among reviewers, with results analyzed using the standardized mean difference (SMD). Subgroup, sensitivity analysis, and assessments for publication bias and heterogeneity were also conducted.
Results: The analysis included 14 RCTs. Iron supplementation significantly improved attention and concentration across all participants (SMD 0.59, 95% CI 0.29 to 0.90) without heterogeneity. In anaemic individuals, supplementation led to an increase in IQ by 2.5 points (95% CI 1.24 to 3.76), while no improvements were observed in non-anaemic participants, nor in memory, psychomotor skills, or scholastic achievement. The funnel plot indicated modest evidence of publication bias, and the included studies had limitations in sample sizes, duration, and methodological rigor.
Conclusion: Evidence suggests that oral iron supplementation may enhance attention, concentration, and IQ in certain groups, especially anaemic individuals. However, further research is needed through larger, blinded, and independently funded RCTs lasting at least a year, encompassing a wider range of ages and varying baseline iron statuses to confirm these findings.
Sources: Falkingham, M., Abdelhamid, A., Curtis, P., Fairweather-Tait, S., Dye, L., & Hooper, L. (2010). The effects of oral iron supplementation on cognition in older children and adults: a systematic review and meta-analysis. Nutrition Journal, 9, 4. DOI: 10.1186/1475-2891-9-4.
MAGNESIUM
Higher magnesium intake is associated with lower fasting glucose and insulin, with no evidence of interaction with select genetic loci, in a meta-analysis of 15 CHARGE Consortium Studies
Abstract
This study investigates the relationship between magnesium intake and glycemic traits such as fasting glucose and insulin levels while exploring potential interactions with specific genetic variants (SNPs) relevant to glycemic traits and magnesium metabolism.
Methods: Data were extracted from 15 studies within the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium, comprising up to 52,684 participants of European descent without known diabetes. The analysis utilized fixed-effects meta-analyses to assess: 1) the association of dietary magnesium intake with fasting glucose (mmol/L) and insulin (ln-pmol/L), and 2) interactions between magnesium intake and genetic variants linked to fasting glucose (16 SNPs), insulin (2 SNPs), or magnesium metabolism (8 SNPs).
Results: Adjusting for age, sex, energy intake, BMI, and behavioral risk factors, magnesium intake showed a significant inverse relationship with fasting glucose (β = -0.009 mmol/L, 95% CI: -0.013 to -0.005, P < 0.0001) and insulin levels (β = -0.020 ln-pmol/L, 95% CI: -0.024 to -0.017, P < 0.0001). While no SNP interactions were statistically significant post-correction for multiple testing, a nominal association was found for SNP rs2274924 in the TRPM6 gene with glucose levels (uncorrected P = 0.03). Additionally, SNPs rs11558471 in SLC30A8 and rs3740393 near CNNM2 indicated nominal interactions with magnesium on fasting glucose (both uncorrected P = 0.02).
Conclusion: The findings align with previous literature suggesting that higher magnesium intake is associated with lower fasting glucose and insulin levels. While the study found some nominal evidence for genetic influence, particularly from TRPM6, further research is necessary to fully understand the interplay between magnesium intake and genetic factors affecting glycemic traits.
Sources: Hruby, A., Ngwa, J. S., Renström, F., Wojczynski, M. K., Ganna, A., Hallmans, G., Houston, D. K., Jacques, P. F., Kanoni, S., Lehtimäki, T., Lemaitre, R. N., Manichaikul, A., North, K. E., Ntalla, I., Sonestedt, E., Tanaka, T., van Rooij, F. J. A., Bandinelli, S., Djoussé, L., Grigoriou, E., Johansson, I., Lohman, K. K., Pankow, J. S., Raitakari, O. T., Riserus, U., Yannakoulia, M., Zillikens, M. C., Hassanali, N., Liu, Y., Mozaffarian, D., Papoutsakis, C., Syvänen, A.-C., Uitterlinden, A. G., Viikari, J., Groves, C. J., Hofman, A., Lind, L., McCarthy, M. I., Mikkilä, V., Mukamal, K., Franco, O. H., Borecki, I. B., Cupples, L. A., Dedoussis, G. V., Ferrucci, L., Hu, F. B., Ingelsson, E., Kähönen, M., Kao, W. H. L., Kritchevsky, S. B., Orho-Melander, M., Prokopenko, I., Rotter, J. I., Siscovick, D. S., Witteman, J. C., Franks, P. W., Meigs, J. B., McKeown, N. M., & (2010). Higher magnesium intake is associated with lower fasting glucose and insulin, with no evidence of interaction with select genetic loci, in a meta-analysis of 15 CHARGE Consortium Studies. The Journal of Nutrition, 9, 4. DOI: 10.3945/jn.112.172049.
An update on magnesium and bone health
Abstract
This narrative review evaluates the relationship between dietary magnesium (Mg) intake, blood Mg levels, Mg supplementation, and bone health since the European Food Safety Authority (EFSA) established a link between Mg intake and bone maintenance in 2009. The review synthesizes findings from 28 studies, highlighting the prevalence of hypomagnesaemia among individuals, particularly postmenopausal women, and its association with osteoporosis. It also explores the effects of Mg supplementation on bone mineral density (BMD) and fracture risk.
Methods: A narrative review format was utilized, examining studies published since 2009 concerning Mg levels, dietary intake, and supplementation. The search strategy included relevant keywords and focused on human studies. A total of 28 studies were included: nine focused on blood Mg levels, 12 on dietary intake, and seven on supplementation—whether alone or in combination with other nutrients.
Results: Studies indicated that lower serum Mg levels are associated with osteoporosis, with 30-40% of postmenopausal subjects exhibiting hypomagnesaemia.
Dietary surveys revealed that approximately 20% of individuals consistently consume less Mg than recommended, correlating with lower BMD and higher fracture risk.
Mg supplementation studies demonstrated positive effects on BMD and fracture risk, using various forms of supplementation (citrate, carbonate, oxide) at doses ranging from 250 to 1800 mg.
Notable findings included significant increases in BMD and reductions in bone turnover markers in postmenopausal women receiving Mg supplementation.
Conclusion: The collective evidence supports the critical role of magnesium in maintaining bone health. Many individuals, particularly postmenopausal women, are at risk of Mg deficiency, which negatively impacts bone density. Mg supplementation shows promise in improving bone health outcomes, but further research with larger, well-designed studies is needed to establish optimal supplementation strategies and understand the mechanisms involved.
Sources: Rondanelli, M., Faliva, M. A., Tartara, A., Gasparri, C., Perna, S., Infantino, V., Riva, A., Petrangolini, G., Peroni, G. (2021). An update on magnesium and bone health. Nutrients, 13(2), PMID: 33959846, PMCID: PMC8313472. DOI: 10.3390/nu13020474.
The Effects of Magnesium Supplementation on Subjective Anxiety and Stress—A Systematic Review
Abstract
Anxiety disorders are prevalent, affecting over 15% of the population. This systematic review examines the evidence for magnesium (Mg) supplementation as a potential treatment for anxiety symptoms. Eighteen studies were included, focusing on populations vulnerable to anxiety, such as those with mild anxiety, premenstrual syndrome (PMS), postpartum status, and hypertension. Positive effects of Mg on subjective anxiety outcomes were noted in several studies, although no effects were observed for postpartum anxiety. Overall, while Mg appears beneficial for anxiety, the quality of evidence is limited, warranting more rigorous randomized controlled trials.
Methods: The systematic search was conducted in May 2016 across multiple databases, including Ovid Medline, PsychInfo, Embase, CINAHL, and Cochrane, focusing on studies that administered Mg (alone or with up to five other ingredients) and measured subjective anxiety or stress outcomes. Studies involving individuals with significant health conditions or developmental disorders were excluded.
Results: Of the 18 studies reviewed, ten involved mixed-sex samples, while the remaining were female-focused. Mg doses varied from 46.4 to 600 mg, with magnesium lactate and magnesium oxide being the most common forms. Four out of eight studies involving anxious individuals reported positive outcomes from Mg supplementation. In PMS samples, four of seven studies indicated beneficial effects. However, postpartum anxiety showed no significant improvement with Mg. The reviewed studies lacked standardized measures for stress, complicating the evaluation of Mg's efficacy in this regard.
Conclusion: The evidence for Mg's effectiveness in reducing subjective anxiety symptoms is suggestive but inconclusive, primarily due to methodological shortcomings in the studies. Further high-quality randomized controlled trials are needed to confirm Mg's potential as an adjunct therapy for anxiety and stress management.
Sources: Boyle, N. B., Lawton, C., & Dye, L. (2017). The Effects of Magnesium Supplementation on Subjective Anxiety and Stress—A Systematic Review. Nutrients, 9(5), 429. DOI: 10.3390/nu9050429. PMCID: PMC5452159. PMID: 28445426.
ZINC
Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and Echinacea in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds
Abstract
This review emphasizes the importance of maintaining a healthy immune system to reduce the incidence, severity, and duration of common colds (CC). It examines the roles of Vitamin C, Vitamin D, zinc, and Echinacea in enhancing immune responses. Regular vitamin C supplementation (1-2 g/day) may decrease cold duration in adults (8%) and children (14%). Zinc can shorten colds by approximately 33% when taken within 24 hours of symptom onset. Vitamin D supplementation benefits individuals with deficiency, while Echinacea extract (2400 mg/day for prevention, 4000 mg/day during acute illness) may support cold management. Further research is necessary to optimize recommendations.
Methods: The review includes an analysis of 82 studies to explore how these nutrients affect immune systems' physical barriers, innate, and adaptive immunity. The authors systematically searched for and reviewed relevant literature on the immune responses related to cold episodes.
Results: The findings indicate that regular intake of Vitamin C, zinc, and Vitamin D contributes to enhanced immune function and may prevent or mitigate the common cold. Echinacea also shows potential benefits in preventing or treating colds. Various study results highlight differences in effectiveness based on factors such as dosage, timing, and individual health status.
Conclusion: The combination of these nutrients may be beneficial for preventing and treating common colds. Recommendations include regular supplementation with Vitamin C, timely zinc administration at symptom onset, proper vitamin D dosages for those deficient, and specific Echinacea dosages before or during illness. The current evidence supports the integration of these nutrients into self-care strategies against common colds.
Sources: Mariangela Rondanelli, Alessandra Miccono, Silvia Lamburghini, Ilaria Avanzato, Antonella Riva, Pietro Allegrini, Milena Anna Faliva, Gabriella Peroni, Mara Nichetti, Simone Perna. Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and Echinacea in Three Main Immune Interactive Clusters Involved during an Episode of Common Colds. PMCID: PMC5949172, PMID: 29853961.
Analysis of Serum Zinc and Copper Concentrations in Hair Loss
Abstract
This study examines the relationship between serum zinc and copper concentrations and various types of hair loss, including alopecia areata (AA), male pattern hair loss, female pattern hair loss, and telogen effluvium (TE). Serum zinc and copper levels were compared between 312 hair loss patients and 30 healthy controls to evaluate their roles in the pathogenesis of hair loss.
Methods: Using data collected from patients diagnosed with different types of hair loss at Hallym University Kangdong Sacred Heart Hospital from 2008 to 2011, serum zinc and copper concentrations were measured. Patients were categorized into four hair loss groups: AA, male pattern (MPHL), female pattern (FPHL), and TE. Statistical analyses compared these concentrations with a control group.
Results: The mean serum zinc level in hair loss patients was significantly lower (84.33 µg/dl) than that of controls (97.94 µg/dl, p=0.002), whereas serum copper levels showed no significant difference (96.44 µg/dl for patients vs. controls). All hair loss groups exhibited lower serum zinc levels compared to controls. The rate of patients with serum zinc concentrations below 70 µg/dl was significantly higher in the AA group (OR 4.02) and TE group (OR 4.65). No correlation was found between zinc and copper concentrations and age.
Conclusion: The findings suggest that low serum zinc levels are associated with certain types of hair loss, notably AA and TE, but serum copper levels do not appear to have a direct relationship with hair loss. The study emphasizes the importance of assessing zinc status in patients with hair loss and suggests further research to explore the role of zinc in hair health.
Sources: Kil, M. S., Kim, C. W., & Kim, S. S. (2014). Analysis of Serum Zinc and Copper Concentrations in Hair Loss. Annals of Dermatology, 26(3), 404-410. DOI: 10.5021/ad.2014.26.3.404. PMCID: PMC3870206. PMID: 24371385.
Effects of Zinc Supplementation on Diabetes Mellitus: A Systematic Review and Meta-Analysis
Abstract
The prevalence of diabetes and prediabetes is rapidly increasing. This systematic review aims to evaluate the effects of zinc supplementation on diabetes management. A comprehensive search identified 25 studies (22 on type-2 diabetes and 3 on type-1 diabetes) that assessed zinc's impact on various clinical and biochemical parameters. The results indicated that zinc supplementation significantly reduced fasting blood glucose (FBG), postprandial blood glucose, and HbA1c levels. Moreover, zinc was found to improve lipid profiles, with notable reductions in total cholesterol and low-density lipoprotein cholesterol. While the evidence suggests beneficial metabolic effects of zinc in diabetes management, the heterogeneity of studies highlights the need for further research.
Methods: A systematic search for studies investigating zinc supplementation and its effects on diabetes was conducted using databases including PubMed, Web of Science, and SciVerse Scopus. The analysis focused on clinical parameters like FBG, 2-hour post-prandial blood glucose, glycated haemoglobin (HbA1c), and lipid parameters. Data extraction and meta-analysis were performed with a focus on assessing the overall efficacy of zinc supplementation in diabetes management.
Results: The review included 25 studies, with 12 studies focusing on FBG among type-2 diabetes patients showing a pooled mean difference of 18.13 mg/dl in favor of zinc supplementation. The reduction in HbA1c was significant at 0.54%. Eight studies on lipid parameters indicated a pooled mean difference of 32.37 mg/dl for total cholesterol and 11.19 mg/dl for low-density lipoprotein cholesterol, also favoring zinc supplementation. Additionally, significant reductions in both systolic and diastolic blood pressures were observed. The findings underscore zinc's potential role in improving glycemic control and lipid profiles.
Conclusion: Zinc supplementation demonstrates significant benefits for glycemic control and lipid parameters in diabetes patients. However, considerable heterogeneity among studies necessitates further investigations to elucidate the underlying biological mechanisms. Robust, well-designed randomized controlled trials are essential to confirm these findings, particularly in prediabetic populations.
Sources: Jayawardena, R., Ranasinghe, P., Galappatthy, P., Malkanthi, R.L.D.K., Constantine, G.R., Katulanda, P. (2012). Effects of zinc supplementation on diabetes mellitus: A systematic review and meta-analysis. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy, 5, 765–778. PMID: 22515411, PMCID: PMC3407731. DOI: 10.2147/DMSO.S31798.
Zinc Lozenges and the Common Cold: A Meta-Analysis Comparing Zinc Acetate and Zinc Gluconate, and the Role of Zinc Dosage
Abstract
The objective of this meta-analysis was to compare the efficacy of zinc acetate lozenges with zinc gluconate lozenges in treating the common cold while examining the dose-dependency of the effect. It aimed to determine the impact of various zinc preparations on the duration of colds based on pooled data from randomized trials.
Methods: This analysis included placebo-controlled trials that administered zinc lozenges with doses exceeding 75 mg/day. The efficacy of zinc on cold duration was computed using the inverse-variance random-effects method, analyzing data from seven randomized trials that involved 575 participants suffering from naturally acquired common colds.
Results: Findings revealed that zinc lozenges reduced the mean common cold duration by 33% (95% CI 21% to 45%). Specifically, lozenges with zinc acetate shortened colds by 40%, while those with zinc gluconate reduced duration by 28%. However, the difference in efficacy between the two types was not statistically significant. Trials using zinc doses of 80-92 mg/day shortened cold duration by 33%, while those using higher doses of 192-207 mg/day found a reduction of 35%, with no significant difference between high and low doses.
Conclusion: The analysis concluded that zinc gluconate lozenges can be as effective as zinc acetate lozenges for alleviating common cold symptoms. There is no evidence supporting that doses above 100 mg/day provide additional benefits in cold treatment. Recommendations for common cold patients to use zinc lozenges are supported, but further research is needed to refine optimal lozenge composition and dosing strategies.
Sources: Harri Hemilä. Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. DOI: 10.1177/2054270417694291, PMID: 28515951, PMCID: PMC5418896.
References:
- https://pubmed.ncbi.nlm.nih.gov/29099763/
- https://pubmed.ncbi.nlm.nih.gov/28805671/
- https://pubmed.ncbi.nlm.nih.gov/20646224/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9324272/
- https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005532.pub3/full
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5949172/
- https://pubmed.ncbi.nlm.nih.gov/34967304/
- https://www.mdpi.com/2072-6643/12/8/2394
- https://pubmed.ncbi.nlm.nih.gov/27625563/
- https://pubmed.ncbi.nlm.nih.gov/29633370/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8711703/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7281985/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC6266234/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC7011499/
- https://pubmed.ncbi.nlm.nih.gov/32060566/
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2020.562051/full
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8467949/
- https://www.jstage.jst.go.jp/article/jnsv/65/6/65_507/_article
- https://pubmed.ncbi.nlm.nih.gov/19923379/
- https://pubmed.ncbi.nlm.nih.gov/18655403/
- https://drc.bmj.com/content/8/1/e001423
- https://pubmed.ncbi.nlm.nih.gov/26510847/
- https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009747.pub2/full
- https://link.springer.com/article/10.1186/1475-2891-9-4
- https://pubmed.ncbi.nlm.nih.gov/23343670/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8313472/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5452159/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3870206/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3407731/
- https://pubmed.ncbi.nlm.nih.gov/26828517/
- https://pubmed.ncbi.nlm.nih.gov/23378454/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4828511/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10084986/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8483258/
- https://www.mdpi.com/2072-6643/17/13/2073
- https://www.mdpi.com/1422-0067/26/15/7159
- https://foodandnutritionresearch.net/index.php/fnr/article/view/10359/16617
- https://www.mdpi.com/1422-0067/26/16/7703
- https://www.mdpi.com/2072-6643/17/12/1982
- https://www.sciencedirect.com/science/article/abs/pii/S2211926423003399
- https://www.mdpi.com/2304-8158/13/14/2255
- https://www.mdpi.com/2072-6643/17/13/2206
- https://www.sciencedirect.com/science/article/abs/pii/S019701862500035X
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5949172/#abstract1
- https://www.ncbi.nlm.nih.gov/books/NBK74011/
- https://www.ncbi.nlm.nih.gov/books/NBK470460/#:~:text=Riboflavin%2C%20vitamin%20B2%2C%20is%20a,%2C%20healthy%20skin%2C%20and%20hair
- https://pubmed.ncbi.nlm.nih.gov/28515951/