From A to E: Uniting vitamins against stroke risk—A systematic review and network meta‐analysis

Abstract Background and Aim Stroke represents a significant public health challenge, necessitating the exploration of preventive measures. This network meta‐analysis aimed to assess the efficacy of different vitamin treatments compared to a placebo in preventing stroke. Methods A systematic electronic search in databases including PubMed, EmBASE, Web of Science, clinicaltrials.gov , and Google Scholar until 31 May 2023 was conducted, to identify published studies investigating the association between vitamin intake and the risk of stroke. Pooled risk ratio (RR) with 95% confidence intervals (CIs) was calculated using a frequentist network meta‐analysis. Furthermore, we ranked vitamins based on p ‐scores, facilitating a comparative assessment of their effectiveness in preventing stroke. Results A total of 56 studies, including 17 randomized controlled trials (RCTs) and 39 cohort studies were analyzed. Direct estimates obtained from network meta‐analysis, we found that vitamin A (RR: .81 [.72–.91]), vitamin B‐complex (RR: .85 [.74–.97]), vitamin B 6 (RR: 79 [.68–.92]), folate (RR: .86 [.75–.97]), vitamin C (RR: .77 [.70–.85]) and vitamin D (RR: .73 [.64–.83]) were significantly associated with a decreased stroke risk. However, no significant association was observed for vitamin B 2 , vitamin B 12 , and vitamin E. Subsequent to network meta‐analysis, vitamins were ranked in decreasing order of their efficacy in stroke prevention based on p ‐score, with vitamin D ( p ‐score = .91), vitamin C ( p ‐score = .79), vitamin B 6 ( p ‐score = .70), vitamin A ( p ‐score = .65), vitamin B‐complex ( p ‐score = .53), folate ( p ‐score = .49), vitamin B 2 ( p ‐score = .39), vitamin E ( p ‐score = .28), vitamin B 12 (.13) and placebo (.10). Conclusion Our study has established noteworthy connections between vitamin A, vitamin B‐complex, vitamin B 6 , folate, vitamin C, and vitamin D in the realm of stroke prevention. These findings add substantial weight to the accumulating evidence supporting the potential advantages of vitamin interventions in mitigating the risk of stroke. However, to solidify and validate these observations, additional research is imperative. Well‐designed clinical trials or cohort studies are needed to further explore these associations and formulate clear guidelines for incorporating vitamin supplementation into effective stroke prevention strategies.