Catherine M. Gordon, MD, MSc, Director, Division of Adolescent Medicine, Department of Pediatrics, Hasbro Children's Hospital, Professor of Pediatrics, Brown University, Providence, RI, USAMeryl LeBoff, MD, Director, Skeletal Health and Osteoporosis Center, Director, Bone Density Unit, Chief, Calcium and Bone Section, Professor of Medicine, Harvard Medical School, Distinguished Chair in Skeletal Health and Osteoporosis, Endocrine, Diabetes and Hypertension Division, Department of Medicine, Brigham and Women's Hospital (BWH), Boston, MA, USA