Association of 25-hydroxyvitamin D with Hb and lead in children: a Chinese population-based study

Objective: To evaluate the prevalence of vitamin D deficiency and insufficiency, as well as their association with Hb and elevated blood lead levels (BLL) in children in China. Design: A cross-sectional and 1-year retrospective study. Setting: Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, China. Subjects: Children aged from 6 months to 14 years living in south-west China who were taken to physical examinations (January-December 2011). Results: Of 1218 children included in the study, 25-hydroxyvitamin D (25(OH) D) concentration (mean 33.18 (SD 16.48) ng/ml) was deficient in 21.6% and insufficient in 27.4%, which were higher than the prevalence of both anaemia at 8? 5% and elevated BLL (Pb$ 10mg/dl) at 1.8%, but lower than mildly elevated BLL prevalence (5mg/dl# Pb, 10 mg/dl) at 56.9%. There was a negative correlation between 25(OH) D concentration and BLL (r520.216, P, 0? 001) while no significant relationship was found between 25(OH) D concentration and Hb (r520? 012, P. 0? 05). After multivariable adjustment, the significant predictors of 25(OH) D deficiency and insufficiency were increasing child age especially between 8 and 14 years (OR518? 29; 95% CI 10? 14, 32? 99; P, 0? 001) and BLL (OR51? 01; 95% CI 1? 00, 1? 02; P50? 045). Conclusions: The prevalence of 25(OH) D deficiency and insufficiency was much higher than that of anaemia or elevated BLL in south-west China, and associated with increasing age and BLL.