Vitamin D3 Supplementation in Participants Diagnosed With Early-Stage Prostate Cancer Who Decide to Undergo Active Surveillance Treatment Regimen.
Vitamin D3 Supplementation in Participants Diagnosed With Early-Stage Prostate Cancer Who Decide to Undergo Active Surveillance Treatment Regimen.
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.
Inclusion Criteria:

 -  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