Excess calcium intake appears to increase the risk of prostate cancer:
A study which evaluated a cohort of over 65,000 men over a period of 6-7 years revealed that intake of calcium over 2000 mg per day in the form of dietary and supplement intake was associated with a moderate increase in risk of prostate cancer. The risk of prostate cancer was not increased with dairy intake. There was also no increase in risk of prostate cancer with moderate or low levels of dietary calcium intake. (31)
Chung et al reviewed calcium and prostate cancer risk as part of a systematic review of health outcomes. He found that a number of studies reported that high calcium intakes were associated with an increased risk of prostate cancer. (32)