New research shows that prescribing calcium and vitamin D supplements for men at risk of bone loss from hormonal treatment for prostate cancer did not prevent bone loss. In fact, the research suggests the supplements can increase the risk of cardiovascular disease and aggressive prostate cancer for these patients. The study from epidemiologists at Wake Forest Baptist Medical Center was published online in the July issue of the journal The Oncologist.
“It wouldn’t be so bad if there simply was no obvious benefit,” said Gary G. Schwartz, PhD, a prostate cancer epidemiologist at Wake Forest Baptist and lead author of the study. “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.”
A side effect of androgen deprivation therapy (ADT), the mainstay treatment for men with advanced prostate cancer, is bone loss. Consequently, many physicians recommend calcium and vitamin D supplements to help reduce fracture risk in these men, because 1 in 10 will experience a fracture within 2 years of therapy.
In the study, the researchers reviewed the results of 12 clinical trials of supplemental calcium and/or vitamin D in a total of 2399 men with prostate cancer undergoing ADT, the measurements of bone mineral density before and after ADT, and the guidelines for calcium and/or vitamin D supplementation.
“We used these data to determine whether calcium and vitamin D supplements prevented bone loss in these men,” Mridul Datta, PhD, coauthor of the study and a postdoctoral fellow who works with Schwartz at Wake Forest Baptist said.
The study showed that at the doses commonly recommended (500-1000 mg of calcium and 200-500 IU of vitamin D per day), men undergoing ADT lost bone mineral density.
“The lack of an obvious benefit is worrisome because other data show an association between increased dietary calcium and an increased risk of aggressive prostate cancer and heart disease,” Schwartz said.
Further research is needed to verify these findings, he said. The next step would include comparing a group treated with calcium and vitamin D supplements with a nonsupplemented group and looking not only at the potential benefits but also at the possible risks.
Source: Wake Forest Baptist Medical Center.