(NBC) - New research suggests Vitamin E may raise the likelihood a man will develop prostate cancer. For the past decade or so, doctors believed Vitamin E might reduce the risk for prostate cancer. But that belief has been challenged by a large study from the Cleveland Clinic's Dr. Eric Klein.
"The finding was a bit of a surprise," said Dr. Klein.
Dr. Klein and his colleagues have been following a group of about 35,000 for at least seven years to study potential benefits of supplemental use of Vitamin E or Selenium. Neither pill reduced the risk for prostate cancer and the men were advised to stay away from the supplements.
But even after the men stopped taking the supplements, researchers found this that men who took Vitamin E alone had a 17% higher chance of being diagnosed with prostate cancer. What they don't know is why.
This is the latest in a string of recent studies that have suggested Americans' use of vitamins is leading to overkill, literally. On Monday, researchers said daily doses of multivitamins and other minerals like iron appear to raise the risk of an early death in older women.
A study from the National Institutes of Health found most people who take dietary supplements don't need them because they tend to eat healthy diets which are full of all the nutrients their bodies need.
The Vitamin E supplement in the Cleveland Clinic trial was 400 international units and was available over the counter. Most multivitamins, however, contain much less, which experts say is a much more appropriate dose.
The Council for Responsible Nutrition, which represents the dietary supplement industry, discourages men from "rushing to judgment" and would like to see additional research into the link between Vitamin E and prostate cancer.