To explore the link between multivitamins and prostate cancer, scientists at the National Cancer Institute studied 295,344 men who participated in the National Institutes of Health–AARP Diet and Health Study. At the start of the study, the men were between the ages of 50 and 71 and free of cancer. After five years of follow-up, scientists found no link between multivitamin use and the risk of developing localized prostate cancer. But compared with men who did not take multivitamins, men who took them more than seven times a week were 32% more likely to develop advanced prostate cancer and 98% more likely to die from the disease.
The results are cause for concern, but not alarm. The apparent link between heavy multivitamin use and advanced or fatal prostate cancer was strongest in men with a family history of the disease (who have an increased risk already) and those who took one or more additional supplements. Men who take lots of supplements may have premonitory symptoms or other reasons to worry about their prostate. The study was not designed to determine whether the vitamins caused the cancers. Nor did it learn which multivitamins the men took, how long they had been taking them, or whether they continued to use them during the follow-up period.
Source: Lawson KA, Wright ME, Subar A, et al. Multivitamin Use and Risk of Prostate Cancer in the National Institutes of Health–AARP Diet and Health Study. Journal of the National Cancer Institute 2007;99:754–64. PMID: 17505071.
Originally published April 2009; last reviewed February 24, 2011.