Calcium and Vitamin D supplements, which are often given to prostate-cancer patients to counteract the effects of the illness, may actually help the cancer grow, according to a new study.
Researchers at Wake Forest Baptist Medical Center who analyzed 12 previous studies on the effects of calcium for prostate-cancer patients also said that the supplements appeared to increase the risk of cardiovascular disease.
Treatment of prostate cancer often involves the reduction of the male hormone androgen, because the illness needs certain levels of androgen to survive. A side effect of what’s known as androgen reduction treatment (ADT) is osteoporosis. So patients often take calcium and vitamin D supplements to keep up bone strength.
An estimated one third of prostate-cancer patients are treated with ADT; the treatment focuses on men with advanced stages of the disease.
But the study, published in the journal “The Oncologist,” found that patients who were undergoing ADT and took the recommended daily dosage of the supplements – 500 to 1,000 mg of calcium and 200 to 500 IU of vitamin D – lost bone density.
“It wouldn’t be so bad if there simply was no obvious benefit,” lead author Gary G. Schwartz said in a statement. "The problem is that there is evidence that calcium supplements increase the risk of cardiovascular disease and aggressive prostate cancer, the very disease that we are trying to treat."
Schwartz said further research is needed to verify the findings.
