O2084: Effect of Serum Vitamin D Levels in Pediatric Fracture Occurrence

Background: Emphasis on bone health for fracture prevention has largely focused on post-menopausal women, however the significance of low vitamin D in pediatric fracture studies has received much less attention. While vitamin D supplementation is not preventative of fragility fractures in older patients, few studies have evaluated its effect on fracture occurrence in growing children. We investigate whether vitamin D levels affect pediatric fracture occurrence.

Methods: A retrospective cohort study was conducted to determine the effect of vitamin D levels on fracture occurrence using an aggregate electronic health record network of >95 million patients. Patients with low vitamin D were confirmed by two sequential lab findings of deficient vitamin D levels ( < 20ng/mL). Patients were categorized based on age (5-9 year, 10-14 years, 15-18 years) and fracture location (upper, lower extremity). A single-institution prospective cohort study of 55 patients was performed was performed to identify contributors to fracture occurrence including mechanism of injury (low vs high energy), type of injury (fracture, sprain/strain, no injury), BMI, diet, and seasonal differences.

Results: Vitamin D-deficiency was associated with increased fracture occurrence in all age groups, with the largest effect in peripubertal children ages 10-14 years (Figure 1). Vitamin D-deficient children subsequently treated with supplemented cholecalciferol demonstrated fracture rates equivalent to vitamin D-sufficient children. For the prospective cohort there were no significant differences in serum vitamin D levels among uninjured children, injured children without fracture, injured children with a fracture. Subset analysis revealed a significant difference in vitamin D levels between injured children with a fracture sustained by a low energy mechanism vs. a high energy mechanism (19.8 vs 30.6 ng/mL, p=0.029).

Conclusion: : Low vitamin D is associated with increased fracture risk in pediatric patients who sustain low energy mechanisms of injury. Vitamin D supplementation may decrease fracture risk in vitamin D-deficient children. These results may shift clinical practice to recommend supplementary vitamin D as a safe, cost-effective intervention to prevent pediatric fractures and improve bone health.