Editorial: The Hazards of Vitamin E
November 14, 2004
Millions of Americans take big doses of vitamin E with the
unproved assumption that the dietary supplement will
improve their health. Now it turns out that large doses may
actually be harmful.
That perplexing news was delivered by researchers from
Johns Hopkins medical institutions last week, in a
scientific talk and medical journal article that combined
and reanalyzed the results of 19 studies involving some
136,000 people in North America, Europe and China. The
researchers concluded that daily doses of 400 international
units and above, the amount typically contained in vitamin
E capsules, slightly increased the risk of dying from all
causes. Those who took the high doses experienced 39
additional deaths per 10,000 people compared with those who
took no supplements.
There are reasons to be cautious in generalizing these
findings. Some statisticians find the pooling of results
from disparate studies unpersuasive. Most of the patients
were elderly people suffering from chronic illnesses, so
the relevance to younger and healthier people is uncertain.
The dose of vitamin E in a typical multivitamin pill, about
30 units, is far below the apparent danger zone.
Yet the findings should sound a cautionary note for
millions of people who swallow big-dose vitamin E capsules
as an antidote to ward off heart disease, cancer,
Alzheimer's and even the common cold. There is scant
evidence to support the presumed benefits, and now there is
a signal of potential harm.