1. Division of Pediatric Endocrinology, Department of Women's and Children's Health, Karolinska Institutet , 171 65 Stockholm , Sweden
2. Division of Pediatric Oncology and Surgery, Department of Women's and Children's Health, Karolinska Institutet , 171 65 Stockholm , Sweden
3. Astrid Lindgren Children's Hospital, Karolinska University Hospital , 171 64 Stockholm , Sweden
4. Centre for Bone and Arthritis Research, Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg , 413 45 Gothenburg , Sweden