Relationship between serum 25-hydroxyvitamin D and bone mineral density in children under 7 years old

Abstract:

Objective To evaluate the endogenous vitamin D level and its correlation with bone mineral density（BMD) in children under 7 years old. Methods Totally 6 838 children who visited the Growth and Development Clinic due to "growth retardation, night terrors, hyperhidrosis, and dysphoria" were enrolled in the study. Serum 25-hydroxyvitamin D [25(OH)D] level was measured by chemiluminescence, whereas individual BMD was measured by quantitative ultrasound. Results Among all subjects, serum 25(OH)D level was 34±14 ng/mL, and the Z value of BMD was -0.49±0.54. With increasing age, serum 25(OH)D level and BMD decreased gradually（P<0.01), and the detection rates for vitamin D deficiency and low BMD increased gradually（P<0.01). Compared with those with sufficient vitamin D, children with vitamin D deficiency had a significantly lower BMD（P<0.01) and a significantly higher detection rate for low BMD（P<0.01). 25-(OH)D level showed a positive linear correlation with BMD in children with vitamin D deficiency（P<0.01). Conclusion Preschool and school-age children have severer vitamin D deficiency than infants.Vitamin D level may be correlated with BMD within a certain range.