CHICAGO — A large study involving Tampa's Moffitt Cancer Center found that men who took high doses of vitamin E for about five years had a slightly increased risk of prostate cancer — even after they quit taking the pills.
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.
That means for every 1,000 men who took vitamin E, there were 11 additional cases of prostate cancer, compared with men taking dummy pills.
The study, appearing in Wednesday's Journal of the American Medical Association, involved more than 35,000 healthy men aged 50 and older from the United States, Canada and Puerto Rico. About 120 men participated at Moffitt.
They were randomly assigned to take daily vitamin E or selenium supplements, both pills or dummy pills. The study was halted after about five years.
Moffitt investigator Dr. Julio Pow-Sang cautioned men not to be alarmed. "One would not say that Vitamin E is a bad thing," said Pow-Sang, a urologist and chair of Moffitt's department of genital urinary oncology, noting its presence in many vegetables and foods. And many vitamins include lower doses than the pills studied, he said.
Times staff writer Letitia Stein contributed to this report.