Ask the doctor: Prostate cancer and multivitamins
Q. In the May 2014 issue, you reported on findings from the Selenium and Vitamin E Cancer Prevention Trial (SELECT), which said that taking vitamin E and selenium raises the risk of prostate cancer. My multivitamin contains both of these nutrients. Should I worry?
A. Based on what we know right now, there is no reason to think that a multivitamin would raise your risk of prostate cancer. Standard multivitamins contain less vitamin E and selenium than men took in SELECT. Also, multivitamins have not been linked to an increased risk of prostate cancer. For example, in a study of over 14,000 male physicians, taking a multivitamin (compared to placebo) did not affect the risk of individual cancers, although it reported a very modest reduction in total combined cancers over 11 years. This effect has not been reproduced in other studies.
In SELECT, men also took a daily supplement of 200 micrograms (mcg) of selenium, 400 international units (IU) of vitamin E, or both selenium and vitamin E, every day for years. SELECT found that these doses are associated with a higher rate of prostate cancer, compared with men who did not take supplements.