The effect of B-vitamins on the prevention and treatment of cardiovascular diseases: a systematic review and meta-analysis

Context Previous research evaluating the effects in B-vitamins on the prevention and treatment of cardiovascular disease (CVD) has substantial limitations and lacks recently published large prospective studies; hence, conducting an updated meta-analysis is needed.Objective We investigated the association between vitamin B status and human CVD development in order to provide more specific advice about vitamin B intake for those at risk of CVD.Data Sources Relevant articles were identified by JSTOR, PubMed, and ProQuest databases.Data Extraction Key words used to identify the studies included the different combinations of B-vitamins, folate, folic acid, vitamin B6, vitamin B12, homocysteine, cardiovascular disease, stroke, coronary disease, myocardial infarction, and cerebrovascular and transient ischemic attack. The database search was supplemented by hand-searching of reference lists of selected articles.Data Analysis Pooled estimates were calculated from the mean differences using a random-effects model.Results Supplementation with folic acid was reported to have a clinical benefit of significantly reducing carotid intima-media thickness. Higher intakes of folic acid, vitamin B6, and vitamin B12 were generally associated with a lower risk of CVD in the general population, except in those without normal renal function and those with unstable angina or past non-ST-elevation myocardial infarction.Conclusion Vitamin B supplementation resulted in the greatest cardiovascular benefit in those with normal renal function and without unstable angina or non-ST-elevation myocardial infarction recently. Factors such as age, gender, and genetic polymorphisms contribute to varying effects.