1. Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
2. Study group of Survey and Estimation of Incidence Rate of Childhood Symptomatic Vitamin D
3. Department of Public Health, Jichi Medical University, Tochigi 329-0498, Japan
4. Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima 770-8503, Japan
5. Department of Pediatric Endocrinology and Environmental Medicine, Tohoku University Graduate School of Medicine, Miyagi 980-8575, Japan
6. Division of Endocrinology and Metabolism, Tokyo Metropolitan Children’s Medical Center, Tokyo 183-8561, Japan
7. Department of Pediatrics, Oita University Faculty of Medicine, Oita 879-5593, Japan
8. Department of Pediatrics, The University of Tokyo Graduate School of Medicine, Tokyo 113-8655, Japan
9. Department of Pediatrics, Dokkyo Medical University, Tochigi 321-0293, Japan
10. Department of Pediatrics, Kyorin University, Tokyo 181-0004, Japan
11. Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Aichi 467-8602, Japan
12. Department of Pediatrics, International University of Health and Welfare, School of Medicine, Chiba 286-8686, Japan
13. Division of Pediatrics, Department of Homeostatic Regulation and Development, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8520, Japan
14. Department of Biostatistics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
15. Department of Orthopedics, Juntendo University Nerima Hospital, Tokyo 177-8521, Japan
16. Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo 113-8431, Japan
17. Department of Pediatrics, Asahikawa Medical University, Hokkaido 078-8510, Japan
18. Department of Pediatrics, Okayama University Hospital, Okayama 700-8558, Japan
19. Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan
20. Division of Pediatric Endocrinology and Metabolism, Children’s Medical Center, Osaka City General Hospital, Osaka 534-0021, Japan
21. Department of Bone and Mineral Research, Research Institute, Osaka Women’s and Children’s Hospital, Osaka 594-1101, Japan