High-dose vitamin E linked to increased mortality

Last Updated: 2004-11-10 10:00:17 -0400 (Reuters Health)

NEW ORLEANS (Reuters Health) - Taking a high dose of vitamin E routinely does not increase your chances of living longer, and in fact it seems to have a negative effect.

Vitamin E supplementation at doses higher than 400 International Units (IU) per day apparently raises all-cause mortality rates and should be avoided, a research team reported at the American Heart Association meeting. Their findings are also being published by the Annals of Internal Medicine online November 10.

Because of its antioxidant properties, vitamin E supplementation has been studied in many trials to prevent chronic diseases. Several of those studies have hinted at increased mortality rates, but the number of participants in the each study was too small to tell if the results were real or occurred by chance.

To further investigate, Dr. Edgar R. Miller III, at Johns Hopkins Medical Institutions in Baltimore, and his team pooled data from 19 trials of vitamin E supplementation. These included nearly 136,000 subjects who were randomly assigned to take vitamin E or placebo capsules and were followed for more than a year.

Overall, vitamin E supplementation did not affect mortality rates, the team found.

However, the 11 trials testing doses of 400 IU daily or higher showed 39 more deaths occurred per 10,000 people taking high-dose vitamin E than among the same number of people taking a placebo.

Miller's group calculates that the risk of dying was increase by 4 percent with high-dose vitamin E.

For low doses of vitamin E -- less than 150 IU daily -- all-cause mortality rates were slightly decreased, although this difference was not significant from a statistical standpoint.

When the researchers factored in the simultaneous use of other vitamins or minerals, the reduction in the risk of dying with low-dosage vitamin E was toned down, but the risk at higher doses was increased.

"On the basis of our study, high-dosage vitamin E supplementation is clearly unjustified," the authors say in their article.

They point out that current guidelines recommend the use of vitamin E to delay the progression of Alzheimer disease, a recommendation that "may be premature until larger randomized, controlled clinical trials evaluate the efficacy and safety of high-dosage vitamin E supplementation."

SOURCE: Annals of Internal Medicine, November 10 online, 2004.

Copyright © 2004 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.