This clinical trial is aimed at measuring the effect of vitamin D3 supplementation on serum prostate-specific antigen (PSA) levels in patients diagnosed with early stage, low-grade, low-risk prostate cancer (Gleason score less than/equal to 6; PSA less than/equal to 10; clinical stage T1C or T2a), who elect to have their disease monitored through active surveillance for at least one year.
lowgrade prostate cancer serum PSA less than/equal to 10 ng/ml Gleason score less than/equal to 6 referred from their treating physician with treatment plan of active surveillance for one year serum creatinine less than/equal to 2.0 mg/dL serum phosphate (measured as phosphorus)greater than 2.3 and less than 4.8 mg/dL serum calcium greater than 8.5 and less than 10.5 mg/dL
Exclusion Criteria:
concurrent malignancy, except non-melanoma skin cancer history of sarcoidosis history of high dose (greater than 1,000 IU daily) vitamin D3 supplementation history of hypercalcemia treatment with lithium medication
