Yuan C, et al. - Authors evaluated the correlation of bioavailable 25(OH)D and vitamin D binding protein (VDBP) levels with risk of advanced and lethal prostate cancer. They also assessed if total 25(OH)D levels interacted with VDBP levels to affect the risk. Men with total 25(OH)D levels and VDBP levels above the median had a multivariable-adjusted OR of 0.31 for advanced prostate cancer vs those with total 25(OH)D levels below the median and VDBP levels above the median (at highest risk). When the analyses were restricted to 116 lethal prostate cancer cases and their controls, similar results were observed. Findings suggested the probability of VDBP levels to modify the association between total 25(OH)D levels and risk of advanced and lethal prostate cancer.