BACKGROUND: Vitamin D supplementation may prevent acute respiratory infections (ARIs). This study aimed to identify the optimal methods of vitamin D supplementation.
METHODS: PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and the ClinicalTrials.gov registry were searched from database inception through July 13, 2023. Randomized-controlled trials (RCTs) were included. Data were pooled using random-effects model. The primary outcome was the proportion of participants with one or more ARIs.
RESULTS: The analysis included 43 RCTs with 49320 participants. Forty RCTs were considered to be at low risk for bias. The main pairwise meta-analysis indicated there were no significant preventive effects of vitamin D supplementation against ARIs (risk ratio [RR]: 0.99, 95% confidence interval [CI]: 0.97 to 1.01, I2 = 49.6%). The subgroup dose-response meta-analysis indicated that the optimal vitamin D supplementation doses ranged between 400-1200 IU/day for both summer-sparing and winter-dominant subgroups. The subgroup pairwise meta-analysis also revealed significant preventive effects of vitamin D supplementation in subgroups of daily dosing (RR: 0.92, 95% CI: 0.85 to 0.99, I2 = 55.7%, number needed to treat [NNT]: 36), trials duration < 4 months (RR: 0.81, 95% CI: 0.67 to 0.97, I2 = 48.8%, NNT: 16), summer-sparing seasons (RR: 0.85, 95% CI: 0.74 to 0.98, I2 = 55.8%, NNT: 26), and winter-dominant seasons (RR: 0.79, 95% CI: 0.71 to 0.89, I2 = 9.7%, NNT: 10).
CONCLUSIONS: Vitamin D supplementation may slightly prevent ARIs when taken daily at doses between 400 and 1200 IU/d during spring, autumn, or winter, which should be further examined in future clinical trials.

The role of dietary vitamins and antioxidants in preventing colorectal cancer (CRC) is a significant area of research within nutritional oncology. However, the relationship between these nutrients and CRC prevention is complex and influenced by factors such as dosage, timing, and individual health status. This review aims to comprehensively analyze and synthesize the existing scientific literature on the potential role of dietary vitamins and antioxidants in preventing CRC. A comprehensive literature review was conducted by searching electronic databases to identify studies examining the prospected impacts of dietary vitamins and antioxidants on the prevention of CRC. According to the outcomes of this review, this research review shows a complex link between vitamins and CRC. While some vitamins such as B2, B6, and D seemed helpful, others such as A and E had mixed results. Vitamin C deficiency was even linked to worse outcomes in cancer patients. Overall, the studies suggest focusing on a balanced diet rich in various vitamins rather than relying solely on individual supplements to prevent CRC. On the other hand, the results of our review suggest that the relationship between antioxidant intake and CRC is more intricate than previously thought. Data from this review indicates that taking specific antioxidant supplements such as selenium and vitamin E does not seem to offer the same protection. This suggests that a balanced diet with a variety of antioxidants is more helpful than focusing on single supplements. While we did not observe a direct association, future studies could investigate how different types and combinations of antioxidants might influence CRC development. In conclusion, the present systematic review highlights the need for more research on the relationship between vitamins, antioxidants, and CRC. We need to understand how these nutrients affect both the survival of people with CRC and the prevention of the disease. This will help us determine the best ways to use vitamins and antioxidants in CRC management and prevention.

BACKGROUND: Telomeres are nucleoprotein complexes at the ends of chromosomes that are under the control of genetic and environmental triggers. Accelerated telomere shortening is causally implicated in the increasing incidence of diseases. The Mediterranean diet has recently been identified as one that confers protection against diseases. This review aimed to identify the effect of each component of the Mediterranean diet on telomere length dynamics, highlighting the underlying molecular mechanisms.
METHODS: PubMed was searched to identify relevant studies to extract data for conducting a narrative review.
RESULTS: The Mediterranean diet alleviates clinical manifestations in many diseases. Focusing on autoimmune diseases, the Mediterranean diet can be protective by preventing inflammation, mitochondrial malfunction, and abnormal telomerase activity. Also, each Mediterranean diet constituent seems to attenuate aging through the sustenance or elongation of telomere length, providing insights into the underlying molecular mechanisms. Polyphenols, vitamins, minerals, and fatty acids seem to be essential in telomere homeostasis, since they inhibit inflammatory responses, DNA damage, oxidative stress, mitochondrial malfunction, and cell death and induce telomerase activation.
CONCLUSIONS: The Mediterranean diet is beneficial for maintaining telomere dynamics and alleviating age-related illnesses. This review provides a comprehensive overview of cross-sectional, observational, and randomized controlled trials regarding the beneficial impact of every constituent in the Mediterranean diet on telomere length and chronic disease management.

There has been increasing interest in the role of micronutrient supplementation in critical care. This narrative review summarizes the recent studies on micronutrients in critically ill patients. We searched two databases for primary randomized controlled trials that investigated the effects of micronutrient supplementation in patients with critical illness published from January 2021 to August 2023. Personal files, reference lists of included studies, and previous reviews were also screened. Twelve studies reported on vitamin C, four studies on vitamin D, three studies on thiamin, two studies on multivitamins, and one study on cobalamin. The therapeutic effects of vitamin C appear mixed, although vitamin C monotherapy appears more promising than vitamin C combination therapy. Intramuscular administration of vitamin D appeared to lower mortality, mechanical ventilation duration, and intensive care unit stay, whereas enteral administration showed limited clinical benefits. Intravenous thiamin was not associated with improved outcomes in patients with septic shock or hypophosphatemia. Preliminary evidence suggests reduced vasopressor dose with cobalamin. Decreased disease severity and hospital stay in patients with COVID-19 with vitamins A-E requires further investigation, whereas providing solely B-group vitamins did not demonstrate therapeutic effects. It is currently premature to endorse the provision of high-dose micronutrients in critical illness to improve clinical outcomes. This review may help to inform the design of future trials that will help better elucidate the optimal dosage and form of micronutrients, methods of administration, and subgroups of patients with critical illness who may most benefit.

BACKGROUND: Pathogenesis of seborrheic dermatitis involves lipid secretion by sebaceous glands, Malassezia colonization, and an inflammatory response with skin barrier disruption. Each of these pathways could be modulated by diet, obesity, and nutritional supplements. Current treatment options provide only temporary control of the condition; thus, it is essential to recognize modifiable lifestyle factors that may play a role in determining disease severity.
OBJECTIVE: This study aimed to summarize published evidence on diet, nutritional supplements, alcohol, obesity, and micronutrients in patients with seborrheic dermatitis and to provide useful insights into areas of further research.
METHODS: A literature search of Scopus, PubMed, and MEDLINE (Ovid interface) for English language papers published between 1993 and 2023 was conducted on April 16, 2023. Case-control studies, cohort studies, and randomized controlled trials with 5 or more subjects conducted on adult participants (>14 years) were included, case reports, case series, and review papers were excluded due to insufficient level of evidence.
RESULTS: A total of 13 studies, 8 case-control, 3 cross-sectional, and 2 randomized controlled trials, involving 13,906 patients were included. Seborrheic dermatitis was correlated with significantly increased copper, manganese, iron, calcium, and magnesium concentrations and significantly lower serum zinc and vitamin D and E concentrations. Adherence to the Western diet was associated with a higher risk for seborrheic dermatitis in female patients and an increased consumption of fruit was associated with a lower risk of seborrheic dermatitis in all patients. The prebiotic Triphala improved patient satisfaction and decreased scalp sebum levels over 8 weeks. Most studies find associations between regular alcohol use and seborrheic dermatitis, but the association between BMI and obesity on seborrheic dermatitis severity and prevalence is mixed.
CONCLUSIONS: This review sheds light on specific promising areas of research that require further study, including the need for interventional studies evaluating serum zinc, vitamin D, and vitamin E supplementation for seborrheic dermatitis. The negative consequences of a Western diet, alcohol use, obesity, and the benefits of fruit consumption are well known; however, to fully understand their specific relationships to seborrheic dermatitis, further cohort or interventional studies are needed.
BACKGROUND: PROSPERO CRD42023417768; https://tinyurl.com/bdcta893.

Aging is a complex process and a significant risk factor for chronic diseases. Menopause, a component of aging in women, is associated with several important cardiometabolic conditions including metabolic syndrome, osteoporosis, and cardiovascular diseases. Menopausal women could benefit from preventative strategies that may decrease morbidity and mortality and improve their quality of life. Vitamins D and K are essential nutrients required for bone health, immune function, and reducing cardiovascular risks, yet their synergistic effect is less understood in aging women. This is the first comprehensive review to summarize the evidence found in randomized clinical trials of the beneficial effects of vitamin D and K co-treatment in postmenopausal women. In our literature search across key electronic databases such as Cochrane, PubMed, and Ovid, we identified 31 pertinent studies. Overall, significant findings indicate that the combined intake of vitamins D and K may positively affect cardiovascular and bone health in postmenopausal women, emphasizing the importance of maintaining a healthy diet rich in vegetables and fermented dairy products. Given the challenges in obtaining all necessary nutrients solely through the diet, vitamin D and K supplements are recommended for postmenopausal women to promote healthy aging and well-being.

Restless legs syndrome (RLS) is a common neurological disorder. It disrupts sleep and well-being and is often associated with other conditions. This review examines the potential of dietary supplements to manage RLS symptoms and reduce reliance on medications. A total of 10 randomized clinical trials involving 482 participants were analyzed, focusing on the impact of various supplements on symptom severity, sleep quality, and daytime sleepiness. Findings suggest some supplements may have positive results. Magnesium oxide and vitamin B6 significantly improved sleep quality and RLS symptoms, with magnesium showing greater effectiveness. Vitamin D supplementation did not show significant benefits. Oral iron has promising results, indicating potential efficacy but issues related to compliance and absorption. Both vitamins C and E positively affect RLS symptoms, likely due to their antioxidant properties. Valerian improved RLS and sleep but did not show a statistically significant improvement. Despite these encouraging results, a high risk of bias was noted in half of the studies, emphasizing the need for more rigorous research. Overall, this review suggests that dietary supplements may be a promising approach to managing RLS. However, further investigation is required to confirm the efficacy and safety.

The pandemic has brought attention to the importance of a healthy immune system in preventing infectious diseases. In this in-depth review, the process by which nutritional interventions and fundamental nutrients affect immune function has been discussed with the goal of enhancing the body\'s natural defenses against viral infections. We explored the complex interplay between diet and immunology, highlighting the essential nutrients, vitamins, minerals, and bioactive substances that are crucial for enhancing immune response. We also investigated the effect of dietary patterns and supplementation methods on immune function. We assessed the effectiveness and potential mechanisms of action of various nutritional therapies in modifying immune responses through a thorough examination of scientific literature. Additionally, we go through the significance of individualized nutrition and highlight possible factors to consider for vulnerable groups, such as the elderly and people with chronic conditions. This review attempts to provide a thorough understanding of the role of diet in boosting immunity by synthesizing available research. It also offers insights into practical methods for enhancing the immune function during the current epidemic and in the future.

Depression is one of the world\'s most prevalent mental disorders and its treatment remains suboptimal. Depression is a systemic disease with highly complex biological mechanisms. Emerging evidence points towards the involvement of mitochondria, microbiome and vitamins in its pathophysiology. Mitochondrial energy production was shown to be lowered in patients with depression. Mitochondrial energy production depends on vitamins, which are available from food, but are also synthesized by the gut microbiota. Several studies reported altered vitamin levels as well as changes in the gut microbiome composition and its vitamin metabolism in patients with depression. Therefore, the question of a connection between mitochondria and gut microbiome and vitamins influencing the mental health arises. This review aims to systematically investigate a combination of the topics - depression, mitochondria, microbiome, and vitamins - to generate an overview of a novel yet extremely complex and interconnected research field. A systematic literature search yielded 34 articles, and the results were summarized and bundled to develop this new integrative perspective on mitochondrial function mediated by the microbiome and microbiome-derived vitamins in depression. Furthermore, by discussing the research gaps this review aims to encourage innovative research approaches to better understand the biology of depression, which could result in optimized therapeutic approaches.

BACKGROUND: Vitamins D, E, A, B, C, and Omega-3 play crucial roles in modulating inflammatory and oxidative stress pathways, both implicated in abdominal aortic aneurysm (AAA) development. Recent research has explored the potential impact of dietary supplements on AAA progression. The systematic review aims to assess interventional studies investigating the effects of various dietary supplements on the development and severity of abdominal aortic aneurysms.
METHODS: A systematic search using relevant keywords related to abdominal aortic aneurysm and dietary supplements was conducted across four databases (PubMed, Embase, Scopus, and Web of Science). Quality assessment for animal studies employed SYRCLE and the Cochrane Collaboration Risk of Bias Tool for randomized control trials. The study protocol is registered in PROSPERO under the registry code CRD42023455958.
RESULTS: Supplementation with Omega-3, Vitamins A, C, D, E, and the Vitamin B family exhibited positive effects in AAA progression. These supplements contributed to a reduction in AAA diameter, elastin degradation, inflammatory responses, and reactive oxygen species. Additional supplements such as Zinc, methionine, and phytoestrogen also played roles in mitigating AAA progression.
CONCLUSIONS: The findings of this study underscore the potential role of dietary supplements in the progression of AAA. Predominantly based on animal studies, the results indicate that these supplements can limit AAA progression, primarily evidenced by their ability to mitigate inflammatory processes and oxidative stress pathways.