There is more evidence that taking vitamin E pills can be risky. A study that followed up on men who took high doses of the vitamin for about five years found they had a slightly increased risk of prostate cancer — even after they quit taking the pills. Doctors say it's another sign that people should be careful about using vitamins and other supplements.
"People tend to think of vitamins as innocuous substances, almost like chicken soup — take a little and it can't hurt," said lead author Dr. Eric Klein of the Cleveland Clinic. The study shows that is not true.
Men randomly assigned to take a 400-unit capsule of vitamin E every day for about five years were 17 percent more likely to get prostate cancer than those given dummy pills. That dose, commonly found in over-the-counter supplements, is almost 20 times higher than the recommended adult amount, which is about 23 units daily.
About 13 percent of American men take it, according to a supplement trade group. Dr. Otis Brawley, chief medical officer for the American Cancer Society, says they should stop taking large doses and talk to their doctors about risks and benefits from prostate cancer screening. Smaller doses, typically found in multivitamins, are probably fine, said Brawley, who was not involved in the research.
Vitamin E is found in foods such as nuts, seeds and vegetable oils. The nutrient helps nerves, muscles, blood vessels and the immune system function. Vitamin E supplements have long been promoted for disease prevention, but scientific research has disproven many claims and suggested they might increase risks for some conditions, including heart failure.