As usual with prostate cancer there is no general agreement about whether or not men who are on a hormone blockade (ADT) to treat prostate cancer should be taking calcium and vitamin D supplements, however there does seem to be some consensus that they should.
Given that there are geographic and seasonal variations in vitamin D levels the issue becomes even more unclear. However, men in North American and Western European are at a higher risk for having low vitamin D levels so calcium and vitamin D are especially important in men receiving bisphosphonates or denosumab.
Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266-281.
Holick MF. Vitamin D: importance in prevention of cancers, type I diabetes, heart disease, and osteoporosis. Am J Clin Nutr. 2004;79(3):362-371.
Joel T Nowak, M.A., M.S.W.
FDA approvesd abiraterone today. Will give many men with metastatic prostate cancer more time–but we still need a cure! http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm253055.htm