PRIMARY OBJECTIVES:~I. Determine the prevalence of vitamin D deficiency among African American (AA) prostate cancer patients.~II. Determine the changes in circulating immunological cell function among patients with vitamin D deficiency and the effects of vitamin D replacement on those changes.~III. Determine the acceptability of cholecalciferol (vitamin D) replacement therapy among AA prostate cancer patients and potential impact on health-related quality of life.~IV. Determine if there are differences in the peripheral blood immunological cell function in AA patients with metastatic prostate cancer compared to those with localized prostate cancer.~OUTLINE:~Patients with low vitamin D3 levels receive cholecalciferol orally (PO) daily for 8 weeks in the absence of unacceptable toxicity.
This early phase I is to find out how common vitamin D deficiency 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 deficiency 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 deficiency which in several studies had been found to contribute to more aggressive prostate cancers.