A striking contrast exists between ...

A striking contrast exists between public enthusiasm for vitamin E correlatives for the prevention and treatment of chronic disease and the evidence from multiple randomized controll trials, which displays no health benefit from their use. novel trials of high-dose vitamin E (400 IU or more through day) have suggested evidence of harm, noting increases in all-cause mortality, which were not statistically significant, compared with patients taking placebo. Miller and colleagues performed a meta-analysis to examine the dose-response relationship between vitamin E supplementation and all-cause mortality.

Nineteen randomized controll trials from 1993 to 2004 met prespecified inclusion criteria, which were all-cause mortality data, a minimum of 10 deaths, and follow-up periods of at least single in kind year. Trial sizes ranged from 196 to 29584 participants. Trials were classified as subdued or high dose based onward an arbitrary cutoff of 400 IU through day. Eight trials were subdued dose; 11 were high dose. The experimental collections in 10 of the trials took other dietary postscripts such as vitamin C, beta-carotene, selenium, and zinc. contemplation populations varied from healthy middle-aged adults to institutionalized older adults with coronary artery disease and other chronic diseases. High-dose trials were more likely to include the latter dispose of patients.

As a whole, all-cause mortality in patients taking vitamin E did not differ from that in the direct groups (pooled risk ratio = 101 P > 2) However, the dose-response analysis observ a progressive increase in all-cause mortality beginning at 150 IU by day and becoming statistically significant at doses of 1100 IU or more by means of day. When results were stratified into low- and high-dose disposes the pooled risk difference for high-dose vitamin E was 39 exces deaths by 10,000 persons (risk ratio = 104 P = 035) compared with placebo.

To direct for the variability across trials, the authors separately analyzed the contribution of each trial to the overall flow Each trial's effect on the overall risk was roughly proportional to its size. The increased mortality associated with high-dose vitamin E persisted level when individual high-dose studies were exclud Controlling for the use of other add tos increased the risk of high-dose vitamin E to 63 exces deaths by 10,000 persons.

In concordance with previous studies, the authors determine that vitamin E supplementation does not cut short mortality. In addition, they debate that their finding of a consistent relationship between increasing amounts of vitamin E and all-cause mortality support the avoidance of fill ups at dosages of 400 IU by day or greater. They caution that this recommendation may not apply to healthy adults, who were included in single two of the 11 high-dose trials.

KENNETH W LIN, MD Miller ER et al. Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern M January 2005;142:37-46

EDITOR'S NOTE: In an accompanying editorial, Greenberg (1) considers on how uncontrolled epidemiologic observations and laboratory experiments firing materialed the widespread belief that high doses of antioxidants like as vitamin E are righteous for one's health. He cautions, however, that the heterogeneity of populations included in this meta-analysis, as well as the concomitant use of other add tos in a majority of the trials, call into question the authors' conclusion that high-dose vitamin E increases all-cause mortality. However, he agrees with the authors that physicians should not prescribe vitamin E continuations to prevent or treat disease.--K.W.L.

REFERENCE

(1) Greenberg ER Vitamin E supplements: convenient in theory, but is the theory good? Ann Intern M 2005;142:75-6

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