Large Doses of Vitamins and Minerals May Put Prostate Cancer Patients at Risk

Large Doses of Vitamins and Minerals May Put Prostate Cancer Patients at Risk

Patients with prostate cancer who are taking excessive amounts of vitamins and minerals may be putting their health at risk, according to the December 2002 issue of the International Journal of Radiation Oncology, Biology and Physics, the official journal of ASTRO, the American Society for Therapeutic Radiology and Oncology.

Tens of thousands of men with prostate cancer are currently engaging in untested medical therapies, such as taking doses of vitamins and minerals that exceed the recommended daily allowance. In addition, herbal mixtures and nonprescription drugs that are not regulated by the Food and Drug Administration have become increasingly popular over the past decade. While patients engage in this self-administration with the intention of advocating for their well-being, they may be unintentionally setting themselves up for complications and adverse effects from conventional cancer therapies.

Researchers documented a case involving a 55-year-old man with localized prostate cancer. Unbeknownst to his physicians, the patient was taking extremely large doses of several vitamins and minerals daily, including 2,250 mg of niacin. The recommended daily allowance of niacin is 12 to 20 mg per day.

The patient was scheduled for brachytherapy, a form of radiation therapy that involves implanting radioactive seeds directly into the prostate gland via needles. The procedure had to be canceled, however, when it was discovered that the patient was at risk for hemorrhage due to a drug interaction between the high dose of niacin and a routinely administered preoperative antibiotic.

"This case illustrates the need for a heightened sense of awareness among patients and physicians regarding how the excessive use of use of vitamins and minerals or the use of untested medicines can have a negative impact on a patient's health," said Anthony V. D'Amico, M.D., Ph.D., of the Department of Radiation Oncology at Brigham and Women's Hospital and Dana-Farber Cancer Institute, and lead author of the study. "Patients and physicians must work together to disclose and discern whether self-administration of unregulated medication is occurring, and, if so, what interactions should be anticipated."

The American Society for Therapeutic Radiology and Oncology is the largest radiation oncology society in the world, with 7,000 members who specialize in treating patients with radiation therapies. As a leading organization in radiation oncology, biology and physics, the Society's mission is to advance the practice of radiation oncology by promoting excellence in patient care, providing opportunities for educational and professional development, promoting research and disseminating research results and representing radiation oncology in a rapidly evolving socioeconomic healthcare environment.