2. Holick MF. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr 2004;80(6 Suppl): 1678S–1688S.
3. Holick MF. Vitamin D deficiency. N Engl J Med 2007;357:266–281.
5. Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2011;96:1911–1930.
6. Srivastava T, Garg U, Ruiz M, Dai H, Alon US. Serum 25(OH)-vitamin D level in children: is there a need to change the reference range based on 2011 Institute of Medicine report? Clin Pediatr (Phila) 2013;52:178–182.
7. Atapattu N, Shaw N, Hogler W. Relationship between serum 25-hydroxyvitamin D and parathyroid hormone in the search for a biochemical definition of vitamin D deficiency in children. Pediatr Res 2013;74:552–556.
8. Lee A, Kim SH, Nam CM, Kim YJ, Joo SH, Lee KR. Prevalence of vitamin D deficiency and insufficiency in Korean children and adolescents and associated factors. Lab Med Online 2016;6:70–78.
9. Choi HS, Oh HJ, Choi H, Choi WH, Kim JG, Kim KM, et al. Vitamin D insufficiency in Korea: a greater threat to younger generation: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008. J Clin Endocrinol Metab 2011;96:643–651.
11. Heaney RP. Functional indices of vitamin D status and ramifications of vitamin D deficiency. Am J Clin Nutr 2004;80(6 Suppl): 1706S–1709S.
12. Harkness L, Cromer B. Low levels of 25-hydroxy vitamin D are associated with elevated parathyroid hormone in healthy adolescent females. Osteoporos Int 2005;16:109–113.
13. Schedewie HK, Odell WD, Fisher DA, Krutzik SR, Dodge M, Cousins L, et al. Parathormone and perinatal calcium homeostasis. Pediatr Res 1979;13:1–6.
16. Crews BO, Moore J, Dietzen DJ. Circulating intact parathyroid hormone is suppressed at 25-hydroxyvitamin D concentrations >25 nmol/L in children. J Pediatr Endocrinol Metab 2014;27:657–660.
17. Malabanan A, Veronikis IE, Holick MF. Redefining vitamin D insufficiency. Lancet 1998;351:805–806.
18. Guillemant J, Taupin P, Le HT, Taright N, Allemandou A, Peres G, et al. Vitamin D status during puberty in French healthy male adolescents. Osteoporos Int 1999;10:222–225.
19. Hill TR, Cotter AA, Mitchell S, Boreham CA, Dubitzky W, Murray L, et al. Vitamin D status and parathyroid hormone relationship in adolescents and its association with bone health parameters: analysis of the Northern Ireland Young Heart's Project. Osteoporos Int 2010;21:695–700.
20. Steingrimsdottir L, Gunnarsson O, Indridason OS, Franzson L, Sigurdsson G. Relationship between serum parathyroid hormone levels, vitamin D sufficiency, and calcium intake. JAMA 2005;294:2336–2341.
21. Gordon CM, DePeter KC, Feldman HA, Grace E, Emans SJ. Prevalence of vitamin D deficiency among healthy adolescents. Arch Pediatr Adolesc Med 2004;158:531–537.
22. Outila TA, Karkkainen MU, Lamberg-Allardt CJ. Vitamin D status affects serum parathyroid hormone concentrations during winter in female adolescents: associations with forearm bone mineral density. Am J Clin Nutr 2001;74:206–210.
23. El-Hajj Fuleihan G, Nabulsi M, Choucair M, Salamoun M, Hajj Shahine C, Kizirian A, et al. Hypovitaminosis D in healthy schoolchildren. Pediatrics 2001;107:E53