Researchers tracked the diet and health of almost 300,000 men and found that about a third reported taking a daily multivitamin, and 5 percent were heavy users, swallowing the pills more than seven times a week.
Nearly 10,241 men had been diagnosed with prostate cancer within five years. Some 1,476 had advanced cancer; 179 died.
It was found that though there is no link between multivitamin use and the risk of localized prostate cancer, there is an increased risk of advanced and fatal prostate cancer among men who used multivitamins more than seven times a week, compared with men who did not use multivitamins.
The link was strongest in men with a family history of prostate cancer and men who also took selenium, beta-carotene, or zinc supplements.
Heavy multivitamin users were almost twice as likely to get fatal prostate cancer as men who never took the pills. However, scientists believe that more rigorous research is needed to further explore the area.
"Because multivitamin supplements consist of a combination of several vitamins and men using high levels of multivitamins were also more likely to take a variety of individual supplements, we were unable to identify or quantify individual components responsible for the associations that we observed," the authors write.
