Study raises concerns about the risks of high doses of vitamin E
High doses of vitamin E may increase all-cause mortality, a study has shown.
Many clinical trials have tested whether vitamin E supplementation can
prevent certain chronic diseases. So researchers at the Johns Hopkins
University in Baltimore, Maryland, analysed mortality rates in 19 randomised
clinical trials with 135,967 participants.
Their analysis showed an increase in risk of death from all causes. For
patients taking high dose vitamin E supplements (>=400IU per day)
for at least one year, when compared with placebo, the risk difference
was 39 per 10,000 persons (95 per cent confidence interval, 3 to 74 per
10,000 persons, P=0.035). Nine out of 11 trials testing vitamin
E doses >= 400IU involved adults with chronic disease and with an average
age of 65 years.
The researchers point out that the effects of lower vitamin E doses (<=
300IU) on mortality rates were inconclusive and risks of high vitamin
E doses
in healthy people are still uncertain. They conclude: “In view
of the increased mortality associated with high doses of beta-carotene
and now vitamin E, use of any high-dosage vitamin supplements should
be discouraged until evidence of efficacy is documented from appropriately
designed clinical trials.”
The study is accessible here |
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