From the Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston (J.E.M.); the Department of Epidemiology and Public Health, Yale Schools of Public Health and Medicine, New Haven, CT (S.T.M.); the Division of Medical Oncology, Ohio State University, Columbus (S.K.C.); and the Institute of Medicine Committee on Dietary Reference Intakes for Vitamin D and Calcium (J.E.M., S.T.M., S.K.C.).