1. Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania , Philadelphia, PA 19104 , USA
2. Departments of Pharmacology and Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, University of Michigan , Ann Arbor, MI 48109 , USA
3. Endocrinology and Metabolism Section, Medical Service, LTC Charles S. Kettles Veteran Affairs Medical Center , Ann Arbor, MI 48015 , USA
4. Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, Division of Endocrinology, Department of Internal Medicine, American University of Beirut , Beirut 1107-2020 , Lebanon
5. ANZAC Research Institute, University of Sydney and Andrology Department, Concord Repatriation General Hospital , Sydney 2139 , Australia
6. Division of Endocrinology, Diabetes, and Metabolism, Johns Hopkins University School of Medicine , Baltimore, MD 21287 , USA
7. Oregon Osteoporosis Center , Portland, OR 97213 , USA
8. Mary MacKillop Institute for Health Research, Australian Catholic University , Melbourne, VIC 3000 , Australia
9. Department of Medicine, University of California, San Diego, School of Medicine , La Jolla, CA 92093 , USA
10. Division of Endocrinology and Metabolism, University of Virginia , Charlottesville, VA 22903 , USA
11. Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital , Boston, MA 02115 , USA
12. Division of Endocrinology and Metabolism, Georgetown University Medical Center , Washington, DC 20057 , USA