Excessive Vitamin Use Can Increase Risk of Aggressive Prostate Cancer

May 17th, 2007

Many people take vitamin supplements daily, believing they will be healthier in the process. No studies have ever shown a true benefit from taking multivitamins and minerals. Some studies have indicated that vitamin A and iron are toxic at high levels. And Beta-carotene can increase the risk of lung cancer in those who smoke.

Taking vitamins will not help those most at risk for prostate cancer to keep from getting it. In fact, a recent study shows it can have the opposite effect.

Researchers followed nearly 300,000 men over a five-year period to uncover a potential link between multivitamins and prostate cancer.  They found no relationship with slow-growing prostate cancer. However, men who took an excessive amount of multivitamins were found to have developed aggressive prostate cancer that had spread beyond the gland or had proved fatal. This association was strongest in men who had a family history of prostate cancer and men who also took selenium, beta-carotene or zinc supplements.

About a third of the men studied took a daily multivitamin, while 5% were heavy users taking more than the recommended doses. Overall, no link was found between multivitamin use and early stage prostate cancer.  The theory is that high-dose vitamins have little effect until a tumor appears, but that their intake then encourages cancer’s rapid growth.

Those who took more than the prescribed dosage on the bottle, one multivitamin a day, increased their risk of aggressive prostate cancer by one-third, and the risk of fatal prostate cancer doubled compared to men who did not take multivitamins.

This year over 250,000 men will be diagnosed and 30,000 will die of prostate cancer.

This study was published in May 2007 and appears in the Journal of the National Cancer Institute.

Sources:  Associated Press; MSNBC

Entry Filed under: CANCER, Prostate Cancer, MEN'S HEALTHCARE, Prostate Cancer