Study questions benefits of vitamin E

NEW ORLEANS - Vitamin E supplements, which millions take in the hope of longer, healthier lives, may do more harm than good.

In fact, people taking high doses of vitamin E might be more likely to die earlier, although the reasons were not clear, said Dr Edgar Miller of Johns Hopkins University in Baltimore.

"I think people take vitamin E because they think it is going to make you live longer, but our study doesn't support that," Dr Miller said.

He and colleagues re-analysed 19 studies of vitamin E and health between 1993 and 2004. The trials involved more than 136,000 mostly elderly patients in North America, Europe and China.

People who took 200 international units (IUs) of vitamin E a day or more died at a higher rate during the study, which lasted three years, than those who did not take supplements.

"It's about a 5 per cent increased risk at 45 years in the trials pooled together," Dr Miller said.

"That doesn't sound like a lot but if you apply it to 25 per cent of the [United States] adult population taking vitamin E, that is significant."

Dr Miller said two-thirds of those taking vitamin E supplements took 400 IU or more.

"We don't think that people need to take vitamin E supplements, that they get enough from the diet," he said. Nuts, oils, whole grains and green leafy vegetables are all rich in vitamin E.

The average US diet supplies six to 10 IU of vitamin E. The Institute of Medicine, which sets recommended doses of vitamins and minerals, gives 1500 IU of E as a daily upper limit.

"I would say it is too high," Dr Miller said.

People take large doses of vitamin E in the belief that it helps counter oxidation by unstable "free radical" molecules, which damage cells and can accelerate ageing and lead to heart disease and cancer.

Dr Miller said there could be several ways the vitamin was damaging to the body. In low doses it was a powerful antioxidant. In higher doses it might promote oxidative damage, and overwhelm the body's natural antioxidants.

Dr. Raymond Gibbons of the Mayo Clinic in Rochester, Minnesota, said the evidence had been building against vitamin E supplements.

"Despite this ... I see many, many patients still taking vitamin E and I have to convince them not to."

- REUTERS