Cholecalciferol

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.