Immunological Effects of Vitamin D Replacement Among Black/African American Prostate Cancer Patients

This early phase I is to find out how common vitamin D insufficiency is among African American patients with a history of prostate cancer that has not spread to other parts of the body (localized) or has spread to other places in the body (metastatic) and how vitamin D insufficiency affects the immune system. This study also aims to find out if replacing vitamin D results in normalization of the immune function. Information from this study may benefit prostate cancer patients by identifying vitamin D insufficiency which in several studies had been found to contribute to more aggressive prostate cancers.

Inclusion Criteria: * Pre-Registration: * African American males, age \>= 18 years * Patients with a previous history of localized or metastatic or locally recurrent prostate cancer * Registration: * Patients with Vitamin D levels below 30 ng/ml Exclusion Criteria: * Pre-Registration: * Known hypersensitivity to vitamin D * End stage renal failure on dialysis * Liver cirrhosis * Currently taking a vitamin D or multivitamin supplement, that has more than 400 IU/10mcg of vitamin D daily for the past month * Legal inability or restricted legal ability, medical or psychological conditions not allowing proper study completion or informed consent signature * Chemotherapy or surgery or radiation within the last 3 weeks prior to blood collection * History of hypercalcemia * Registration: * Chemotherapy or surgery or radiation within the last 3 weeks prior to blood collection