Effect of Vitamin D Deficiency on Development of Slipped Capital Femoral Epiphysis

Objective: Slipped capital femoral epiphysis (SCFE) is one of the most common hip disorders in adolescents, often linked to obesity. However, other factors, such as vitamin D deficiency, may also contribute to SCFE development. This study investigates the impact of vitamin D deficiency on SCFE development in a large cohort. Methods: We utilized the TriNetX national database to query pediatric patients with documented calcidiol levels. Patients with a recorded visit below the age of 9 and subsequent documented calcidiol levels were followed until SCFE occurrence or age 18. Patients were categorized into vitamin D adequate (≥ 30 ng/mL) and deficient (< 30 ng/mL) groups. Propensity score matching was performed using a multivariable logistic regression model to adjust for baseline characteristics, including age, sex, race, and body mass index percentile. Significance testing was conducted using the Fisher exact test and χ2 tests to compare SCFE risk between the cohorts, with a significance level set at P <0.05. Results: On preliminary analysis, 98,045 patients met the inclusion criteria. After matching, 34,552 individuals in both vitamin D deficient and adequate groups were included, with an average age of 8.4 years at the time of their first visit and 50% females. SCFE occurred in 136 (0.39%) and 48 (0.14%) patients in the vitamin D deficient and adequate groups, respectively (P < 0.0001). Vitamin D deficiency significantly increased SCFE risk, with a relative risk of 2.8 (95% CI: 2-3.9; P < 0.0001) and a hazard ratio of 1.6 (95% CI: 1.1-2.2; P < 0.0001). Conclusion: This study, one of the largest to date, establishes a significant association between vitamin D deficiency and SCFE development. After controlling for potential confounding variables, including body mass index, individuals with vitamin D deficiency were ∼2.83 times more likely to develop SCFE. The study findings highlight the need for further research to evaluate whether supplementation could mitigate this risk of developing SCFE.