1. Department of Magee-Womens Research Institute (L.M.B., J.M.C., H.N.S., R.W.P., J.M.R.), Pittsburgh, Pennsylvania 15213
2. Department of Obstetrics, Gynecology, and Reproductive Sciences (L.M.B., J.M.C., H.N.S., R.W.P., J.M.R.), University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
3. Department of Epidemiology (L.M.B., J.M.C., J.M.R.), University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania 15261
4. Department of Vitamin D Laboratory (M.F.H.), Section of Endocrinology, Nutrition and Diabetes, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02115