1. Mayo Clinic Evidence-Based Practice Center , Rochester, MN 55905 , USA
2. School of Population Health, University of Auckland , Auckland 1023 , New Zealand
3. Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences and INFANT Research Centre, University College Cork , Cork T12 Y337 , Ireland
4. Internal Medicine, Endocrine Section, Amsterdam University Medical Center , Amsterdam 1007 MB , The Netherlands
5. Pediatric Endocrine Unit, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114 , USA
6. Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114 , USA
7. Divisions of Endocrinology, Diabetes and Metabolism, Tufts-New England Medical Center , Boston, MA 02116 , USA