METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) of vitamin C versus comparative interventions in patients with COVID-19. The outcome of interest was all-cause mortality.
RESULTS: The meta-analysis of eleven trials using a random-effects model revealed significant reduction in the risk of all-cause mortality with the administration of vitamin C among patients with COVID-19 relative to no vitamin C (pooled odds ratio = 0.53; 95% confidence interval 0.30-0.92). Subgroup analysis of studies that included patients with severe COVID-19 also produced findings of significant mortality reduction with the administration of vitamin C relative to no vitamin C (pooled odds ratio = 0.47; 95% confidence interval 0.26-0.84).
CONCLUSION: Overall, evidence from RCTs suggests a survival benefit for vitamin C in patients with severe COVID-19. However, we should await data from large-scale randomized trials to affirm its mortality benefits.
METHODS: We pooled data from 18 observational studies involving 5592 individuals. Baseline parameters that might have contributed to the significant differences observed were also analyzed.
RESULTS: Patients with OSA had significantly lower serum 25-OHD levels (pooled d + - 0.74 [95% CI: - 1.19 to - 0.28], p
METHODS: A systematic search was performed across online databases including Scopus, Web of Science, and PubMed/Medline to identify relevant randomized controlled trials (RCTs) published until July 2022. A random-effects model was applied for the meta-analysis.
RESULTS: The present meta-analysis included a total of 22 RCTs with 1447 patients diagnosed with T2DM.A pooled analysis revealed a significant decrease in levels of serum hemoglobin A1c (HbA1c), fasting insulin, and fasting blood glucose (FBG) in vitamin C-treated T2DM patients compared with their untreated counterparts. The dose-response evaluation displayed a substantial linear association between the intervention duration and changes in serum HbA1c levels. However, the analysis did not demonstrate any significant effect of vitamin C on serum values of homeostasis model assessment of insulin resistance(HOMA-IR) in diabetic patients. Subgroup analyses indicated that high-dose vitamin C administration (≥1000 mg/d) considerably decreased serum HOMA-IR levels.
CONCLUSION: These findings suggest that long-term (≥12 weeks) and high-dose vitamin C supplementation (≥1000 mg/d) may ameliorate glycemic profile in T2DM patients. However, additional high-quality RCTs are necessary to validate these results.
OBJECTIVE: Herein, we are highlighting the recent knowledge of vitamin D roles and functions with respect to pathophysiological disorders such as cancer, cardiovascular diseases, rheumatoid arthritis (RA) and debate the potential avails of vitamin D on slowing cancer, cardiovascular disease and RA progression.
CONCLUSION: The findings of this review confirm that the importance of vitamin D metabolites or analogues which can provide a helpful platform to target some kinds of cancer, particularly when used in combination with existing therapies. Moreover, the correlation between vitamin D deficiencies with cardiovascular diseases and rheumatoid arthritis (RA) progression might suggest a pivotal role of vitamin D in either initiation or progression of these diseases.