Calcium and vitamin D may hurt, not help, in prostate cancer
Although androgen-deprivation therapy causes loss of bone mineral density (BMD) in men with prostate cancer, supplementation with calcium and/or vitamin D at the commonly recommended doses doesn't prevent BMD loss, and could increase the risks for advanced prostate cancer and cardiovascular disease.
Investigators Mridul Datta, RD, PhD, and Gary G. Schwartz, PhD, of Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, acknowledged in their report for The Oncologist that supplementation with calcium and vitamin D to counteract the bone-related effects of androgen-deprivation therapy seems logical and is advocated by many lay and professional groups. However, their review of guidelines for such supplementation and results of clinical trials evaluating this intervention in men with prostate cancer undergoing androgen-deprivation therapy told a different story.
“We used these data to determine whether calcium and vitamin D supplements prevented bone loss in these men,” noted Datta in a statement issued by Wake Forest. “The answer is clearly ‘No.'”
Specifically, the findings of 12 clinical trials involving 2,399 men with prostate cancer who were undergoing androgen-deprivation therapy showed that these patients lost BMD at the commonly recommended doses of 500 mg/day to 1,000 mg/day for calcium and 200 IU/day to 500 IU/day for vitamin D.
“It wouldn't be so bad if there simply was no obvious benefit,” pointed out Schwartz in the Wake Forest 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.”
Although further research is needed to verify these findings, the authors recommend rigorous evaluation of the presumed benefits of calcium and vitamin D supplementation in men undergoing androgen-deprivation therapy.