Vitamin D Status and Screening Practices Among Pediatric Fracture Patients With Autism Spectrum Disorder: A Retrospective Matched Cohort Study.

Abstract

Vitamin D is essential for pediatric bone health and fracture healing. Children with autism spectrum disorder (ASD) may have risk factors for fracture injuries and vitamin D insufficiency. However, patterns of vitamin D testing and insufficiency among pediatric fracture patients with ASD are not well defined. A single-institution retrospective cohort study of pediatric patients treated for fractures between 2012 and 2024 was conducted. Patients with ASD were compared with an age- and sex-matched cohort without ASD. Chart review identified demographics, comorbidities, medication use, serum 25-hydroxyvitamin D testing, ordering specialty, and supplementation status. Low vitamin D levels were categorized as insufficient and deficient, defined as <30 ng/mL and <20 ng/mL, respectively. Socioeconomic status was assessed using the Area Deprivation Index (ADI) and Childhood Opportunity Index (COI). Cohorts were compared using the χ2 and Fisher exact tests. Logistic regression was used to identify predictors of vitamin D testing and low vitamin D levels. A total of 290 patients (78% male; 145 ASD, 145 non-ASD) were included. Cohorts were similar in age, sex, race/ethnicity, and BMI. Eighty-eight patients (30%) had vitamin D testing, with testing more common among patients with ASD (67 vs. 21, 46% vs. 14%; P<0.001). Low vitamin D was common (46/88, 52%) and did not differ between groups (ASD 36/67, 54% vs. 10/21, 48%; P=0.8). Most testing was ordered by psychiatry, behavioral health, or primary care, while orthopaedic services ordered 4 tests (5%). Multivariable regression identified ASD (OR=3.7, 95% CI: 1.9-7.6) and atypical antipsychotic use (OR=7.6, CI: 2.7-25.1) as predictors of testing. Increasing age (OR=1.2, CI: 1.1-1.4) and worse ADI (OR=1.3, CI: 1.1-1.6) were predictors of low vitamin D. The prevalence of low vitamin D was high among pediatric patients with fractures. Although children with ASD were more frequently tested, the prevalence of low vitamin D was not higher than in children without ASD. Low vitamin D was associated with socioeconomic disadvantage. Screening approaches incorporating socioeconomic risk may complement diagnosis-specific testing practices. Level III-retrospective comparative study.