Pilot study: potential role of vitamin D (Cholecalciferol) in patients with PSA relapse after definitive therapy.

Abstract: When local treatments for prostate cancer have failed, and prostate-specific antigen(PSA) rises in the absence of symptoms, there is little consensus as to the best management strategy. Calcitriolhas been shown to prolong the doubling timeof PSA in this context, but near-toxic doses are required. We investigated the effect of the nutrient vitamin D ( cholecalciferol), a biochemical precursor of calcitriol, on PSA levels and the rate of rise of PSA in these patients. Fifteen patients were given 2,000 IU (50 μg) of cholecalciferoldaily and monitored prospectively every 2-3 mo. In 9 patients, PSA levels decreased or remained unchanged after the commencement of cholecalciferol. This was sustained for as long as 21 mo. Also, there was a statistically significant decrease in the rate of PSA rise after administration of cholecalciferol(P = 0.005) compared with that before cholecalciferol. The median PSA doubling timeincreased from 14.3 mo prior to commencing cholecalciferolto 25 mo after commenci...