male veterans (> 18 years of age) recently diagnosed with low-risk pca (histologically documented adenocarcinoma of the prostate)

a serum psa value of up to 10.0 ng/ml, and a gleason score of six or less (three or less in either architectural pattern)

for the purpose of eligibility, these additional criteria will be verified: *serum creatinine 2.0 mg/dl

serum phosphate (measured as phosphorus) > 2.3 and < 4.8 mg/dl

serum calcium > 8.5 and < 10.5 mg/dl

subjects with any concurrent malignancy, except non-melanoma skin cancer

subjects with a history of sarcoidosis

subjects with a history of high-dose (1,000 iu per day) vitamin d supplementation

subjects with a history of hypercalcemia

subjects who use lithium as a medication