High serum vitamin D levels linked to prostate cancer risk BY DOUG BRUNK
Mounting evidence suggests that there may be an increased risk of prostate cancer among men with the highest levels of vitamin D.
At a public conference on vitamin D sponsored by the National Institutes of Health, Dr. Demetrius Albanes highlighted several studies in the medical literature, including a meta-analysis which found a 1.17-fold increased risk of prostate cancer among men in the highest categories of 25-hydroxy vitamin D [25(OH)D] status. That analysis was based on a review of 21 prospective cohorts involving 11,941 incident cases of prostate cancer (J. Cancer Res. Clin. Oncol. 2014;140:1465-77). Similar findings were observed in an earlier Swedish study (Cancer Causes Control; 2012;23:1377-85).
Genetic variants in four genes have been shown to predict circulating levels of vitamin D: GC, CYP24A1, CYP2R1, and DHCR7. However, a large analysis of cases and controls from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium failed to demonstrate a protective association between loci known to influence vitamin D levels and prostate cancer risk (Cancer Epidemiol. Biomarkers Prev. 2013;22:688-96). In another study, Dr. Albanes and his associates found that serum vitamin D–binding protein (DBP) modified the association between serum 25-hydroxy vitamin D and prostate cancer, with higher risk for elevated 25-hydroxy vitamin D levels observed mainly among men having DBP concentrations above the median (odds ratio, 1.81 for highest vs. lowest quintile; P = .001) (Int. J. Cancer 2013; 132:2940-7).