Inclusion Criteria:  African American males, age >= 18 years Patients with a previous history of localized or metastatic prostate cancer Patient willing to participate in the study and provide informed consent  Exclusion Criteria:  Known hypersensitivity to vitamin D Chemotherapy or surgery or radiation within the last 3 weeks prior to blood collection End stage renal failure on dialysis Liver cirrhosis History of hypercalcemia Legal inability or restricted legal ability. Medical or psychological conditions not allowing proper study completion or informed consent signature