Calcium, dairy products, and the risk of prostate cancer

Background. Calcium intake has been suggested to play a role in the etiology of prostate cancer, since it is inversely related to vitamin D levels, which, in turn, would have an antiproliferative effect on human cancer cell lines. The hypothesis that high calcium and low vitamin D levels are associated with prostate cancer risk, however, remains unconvincingly demonstrated. Methods. This relation was investigated in a case-control study of prostate cancer conducted in Northern Italy between 1985 and 1992 on 288 cases and 762 controls admitted to hospital for acute non-neoplastic diseases. Results. No significant relation was found fur calcium intake: compared to the lowest quintile of intake, the multivariate odds ratios (OR) of prostatic cancer, after adjusting for age, study center, education, body mass index, and meat intake, fur increasing intake quintiles were 1.21, 0.68, 0.64, 1.12, with no trend in risk. The OR was 0.99 for an increment of 500 mg per day of calcium. The risk estimates were consistent in two strata of age (< 65 and greater than or equal to 65 years at diagnosis). Conclusions. Our results do not support an association between calcium and the risk of prostate cancer. However, the present study cannot address the effect of calcium in the ranges where an increased risk of prostate cancer has been noted previously, and with specific reference to advanced disease. (C) 2001 Wiley-Liss, Inc.