Randomized trials of vitamin E in the treatment and prevention of cardiovascular disease.
BACKGROUND
Observational epidemiological studies consistently show that individuals who choose to take high amounts of vitamin E through diet or supplements experience cardiovascular benefits, for which basic research provides plausible mechanisms. However, because the size of the postulated benefit is small to moderate, the confounding inherent in observational studies is as great as the effect size. Before the availability of randomized evidence, about 1 in 4 adults was taking vitamin E supplements in the United States.


METHODS
We conducted a computerized search of the English-language literature from 1990 to the present and found 7 large-scale randomized trials of the effectiveness vitamin E in the treatment and prevention of cardiovascular disease. Data were available on myocardial infarction, stroke, or cardiovascular death.


RESULTS
Six of the 7 trials showed no significant effect of vitamin E on cardiovascular disease. In an overview, vitamin E had neither a statistically significant nor a clinically important effect on any important cardiovascular event (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.94-1.03) or its components: nonfatal myocardial infarction (OR, 1.00; 95% CI, 0.92-1.09), nonfatal stroke (OR, 1.03; 95% CI, 0.93-1.14), or cardiovascular death (OR, 1.00; 95% CI, 0.94-1.05).


CONCLUSIONS
The ORs and CIs provide strong support for a lack of statistically significant or clinically important effects of vitamin E on cardiovascular disease. The use of agents of proven lack of benefit, especially those easily available over the counter, may contribute to underuse of agents of proven benefit and failure to adopt healthy lifestyles.
Eidelman
Rachel S
RS
Agatston Research Institute, Miami Beach, FL, USA.
Hollar
Danielle
D
Hebert
Patricia R
PR
Lamas
Gervasio A
GA
Hennekens
Charles H
CH
D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000188:drug therapy* / Q000517:prevention & control; D016757:Death, Sudden, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D020521:Stroke / Q000188:drug therapy / Q000517:prevention & control; D014810:Vitamin E / Q000627:therapeutic use*
D014810:Vitamin E