To review clinical trials evaluating the safety and efficacy of vitamin E supplementation in cardiovascular disease and cancer prevention.
DATA SOURCES
Using the MeSH search terms alpha-tocopherol, tocopherols, vitamin E, cardiovascular diseases, cancer, malignancy, and clinical trials, a literature review was conducted to identify peer-reviewed articles in MEDLINE (1966–July 2005).
STUDY SELECTION AND DATA EXTRACTION
Published materials including original research, and previous meta-analyses were included. Only English-language articles and trials on vitamin E alone or in combination with other vitamins or minerals were reviewed. Emphasis was placed on prospective, randomized, double-blind, placebo-controlled clinical trials.
DATA SYNTHESIS
Eight clinical studies demonstrated contradicting results regarding the benefits of vitamin E in the prevention of cardiovascular disease and cancer. There is enough evidence from large, well-designed studies to discourage the use of vitamin E in the primary prevention of cardiovascular disease. Secondary prevention requires more adequate clinical trials with selected populations to examine protective effects of vitamin E in cardiovascular disease. The findings of the studies reviewed do not provide evidence that vitamin E may reduce the risk of cancer; thus, at the present time, we do not recommend daily vitamin E intake for cancer prevention is not recommended.
CONCLUSIONS
Available data do not support the supplementation of vitamin E in cardiovascular disease and cancer prevention.
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