OBJECTIVE: To assess the efficacy of vitamin and antioxidant supplements in the 
prevention of cardiovascular diseases.
DESIGN: Meta-analysis of randomised controlled trials.
DATA SOURCES AND STUDY SELECTION: PubMed, EMBASE, the Cochrane Library, Scopus, 
CINAHL, and ClinicalTrials.gov searched in June and November 2012. Two authors 
independently reviewed and selected eligible randomised controlled trials, based 
on predetermined selection criteria.
RESULTS: Out of 2240 articles retrieved from databases and relevant 
bibliographies, 50 randomised controlled trials with 294,478 participants 
(156,663 in intervention groups and 137,815 in control groups) were included in 
the final analyses. In a fixed effect meta-analysis of the 50 trials, 
supplementation with vitamins and antioxidants was not associated with 
reductions in the risk of major cardiovascular events (relative risk 1.00, 95% 
confidence interval 0.98 to 1.02; I(2)=42%). Overall, there was no beneficial 
effect of these supplements in the subgroup meta-analyses by type of prevention, 
type of vitamins and antioxidants, type of cardiovascular outcomes, study 
design, methodological quality, duration of treatment, funding source, provider 
of supplements, type of control, number of participants in each trial, and 
supplements given singly or in combination with other supplements. Among the 
subgroup meta-analyses by type of cardiovascular outcomes, vitamin and 
antioxidant supplementation was associated with a marginally increased risk of 
angina pectoris, while low dose vitamin B(6) supplementation was associated with 
a slightly decreased risk of major cardiovascular events. Those beneficial or 
harmful effects disappeared in subgroup meta-analysis of high quality randomised 
controlled trials within each category. Also, even though supplementation with 
vitamin B(6) was associated with a decreased risk of cardiovascular death in 
high quality trials, and vitamin E supplementation with a decreased risk of 
myocardial infarction, those beneficial effects were seen only in randomised 
controlled trials in which the supplements were supplied by the pharmaceutical 
industry.
CONCLUSION: There is no evidence to support the use of vitamin and antioxidant 
supplements for prevention of cardiovascular diseases.