To evaluate the effect of oral vitamin E supplementation on all-cause mortality in apparently healthy people.
A systematic review and meta-analysis was conducted on randomised controlled trials (RCTs) with ≥ 6 months of follow up investigating the effect of vitamin E supplementation on healthy adults in developed countries. Electronic databases (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials) and reference lists of trial reports were searched for RCTs published between 1966 and June 2012. Three investigators assessed eligibility of identified trials. Disagreements were resolved by consensus. Two investigators independently extracted data according to the criteria.
There were 18 RCTs identified with 142,219 apparently healthy participants (71,116 in vitamin E intervention groups and 71,103 in control groups) that were included in the final analysis. Fixed effect and random effects analysis of the 18 trials revealed that supplementation with vitamin E was not associated with all-cause mortality (relative risk 1.01, 95% confidence interval 0.97 - 1.05, p = 0.65). Subgroup analyses by type of vitamin E (natural or synthetic), dose or duration of exposure, study design or quality, and pre-specified mortality outcome showed no association with all-cause mortality.
The evidence from pooled analysis of 18 randomised controlled trials undertaken in apparently healthy people shows no effect of vitamin E supplementation at a dose of 23-800 IU/day on all-cause mortality.