Rui Qin, Yan Zhao, Yinfang Li, Juhua Yan, Youfang Hu, Hong-ni Yue, Xirong Guo, Yuan Song, Guoqin Liu, Wen Zheng, Mei Zhu, Guanyu Liang, Yanrong Fu, Juan Wen, Hong Hong, Aiping Wu, Chenbo Ji, Heyun Lv, Zi Yang, Yarong Wei, Zhen-Ying Qin, and Yufei Ni
// Yanrong Fu 1, 2, 3, * , Youfang Hu 2, * , Zhenying Qin 2 , Yan Zhao 2 , Zi Yang 2 , Yinfang Li 4 , Guanyu Liang 2 , Heyun Lv 5 , Hong Hong 6 , Yuan Song 7 , Yarong Wei 8 , Hongni Yue 9 , Wen Zheng 10 , Guoqin Liu 11 , Yufei Ni 12 , Mei Zhu 13 , Aiping Wu 14 , Juhua Yan 15 , Chenbo Ji 3 , Xirong Guo 3 , Juan Wen 3 , Rui Qin 2 1 Department of Child Health Care, the Second Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, 210011, China 2 Department of Child Health Care, Jiangsu Women and Children Health Hospital, Women and Child Branch Hospital of Jiangsu Province Hospital, the First Affiliated Hospital with Nanjing Medical University, Nanjing, 210036, China 3 Nanjing Maternity and Child Health Care Institute, Nanjing Maternity and Child Health Care Hospital, Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University, Nanjing, 210029, China 4 Department of Pediatrics, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China 5 Department of Child Health Care, Jiangning Maternity and Child Health Care Institute, Nanjing, 211100, China 6 Department of Child Health Care, Drum Tower Maternity and Child Health Care Institute, Nanjing, 210009, China 7 Department of Child Health Care, Suzhou Municipal Hospital, Suzhou, 215000, China 8 Department of Child Health Care, Wuxi Maternity and Child Health Care Hospital, Wuxi, 214000, China 9 Department of Child Health Care, Huai’an Maternity and Child Health Care Hospital, Huai’an, 223001, China 10 Department of Child Health Care, Yancheng Maternity and Child Health Care Institute, Yancheng, 224000, China 11 Department of Child Health Care, Dafeng Maternity and Child Health Care Hospital, Dafeng, 224100, China 12 Department of Child Health Care, Nantong Maternity and Child Health Care Hospital, Nantong, 226000, China 13 Department of Child Health Care, Xuzhou Children's Hospital, Xuzhou, 221000, China 14 Department of Child Health Care, Xinghua Maternity and Child Health Care Hospital, Xinghua, 225700, China 15 Department of Child Health Care, Kunshan Maternity and Child Health Care Institute, Kunshan, 215300, China * These authors contributed equally to this work Correspondence to: Rui Qin, email: qinrui329@163.com Juan Wen, email: wenj2010@gmail.com Keywords: serum 25-hydoxyvitamin D, bone mineral density, 0-7 year old children Received: September 14, 2016 Accepted: October 28, 2016 Published: November 04, 2016 ABSTRACT Objective: To describe the status of serum 25-hydoxyvitamin D [25(OH)D] concentrations and identify the relationship between 25(OH)D and bone mineral density (BMD). In an effort to explore the appropriate definition of vitamin D (VD) deficiency in 0–7 year old children. Results: The median serum 25(OH)D concentrations was 62.9 nmol/L and 28.9% of the children had a low 25(OH)D (< 50 nmol/L). And a linear relation between 25(OH)D concentrations and BMD was surveyed (r = 0.144 , P < 0.001). After adjusting for the confounders, serum 25(OH)D was positively associated with BMD (β = 172.0, 95%CI = 142.8–201.2, P < 0.001), and low 25(OH)D (< 75 nmol/L) had a high stake for low BMD (OR = 1.424, 95%CI = 1.145–1.769, P = 0.001). Additionally, there was a nonlinear relation between 25(OH)D and low BMD, and a critical value for 25(OH)D of 75 nmol/L appeared for low BMD. The prevalence of low BMD was 14.1% in children with 25(OH)D ≥ 75 nmol/L, much lower than that of the concentrations between 50–75 nmol/L and < 50 nmol/L. Materials and Methods: A total of 4,846 children 0–7 years old were recruited in Jiangsu Province, China. BMD and serum 25(OH)D concentrations were determined by quantitative ultrasound and enzyme-linked immunosorbent assay, respectively. Linear regression and logistic regression analyses were used to assess the association of 25(OH)D concentrations with BMD. Conclusions: Serum 25(OH)D concentrations was related with BMD and 25(OH)D concentrations < 75 nmol/L might be a more appropriate definition of VD deficiency in 0–7 year old children.