Vitamin D Deficiency in Children with Uveitis: A Comparison of Juvenile Idiopathic Arthritis-Associated and Idiopathic Uveitis - A Retrospective Study (2019-2025).

Abstract

Purpose: To assess vitamin D deficiency in pediatric uveitis, compare 25-hydroxyvitamin D (25(OH)D) levels between juvenile idiopathic arthritis (JIA)-associated and idiopathic uveitis, and explore clinical associations.

Methods: Retrospective study of children (0-18 years) with uveitis treated during 2019-2025 at a tertiary eye clinic and affiliated pediatric rheumatology unit. All had documented serum 25(OH)D; deficiency was < 20 ng/mL. Group comparisons, correlations, and exploratory complete-case regression were performed.

Results: Forty-four children were included (21 JIA-associated, 23 idiopathic; 59% female; mean age 9.2 years). Mean 25(OH)D was 23.3 ± 11.5 ng/mL; 52.3% were deficient and 11.4% severely deficient. Idiopathic uveitis had lower unadjusted 25(OH)D than JIA-associated uveitis (median 16.0 vs 30.4 ng/mL; p = 0.002; Cohen's d = 1.0) and higher deficiency frequency (73.9% vs 28.6%; p = 0.006). 25(OH)D correlated inversely with age (ρ =  -0.61; p < 0.001). In complete-case regression (n = 30; R² = 0.47), age remained associated with lower 25(OH)D (β =  -1.5 ng/mL/year; p = 0.022), whereas the adjusted group effect was not statistically significant and imprecise (β = 0.1 ng/mL; 95% CI - 10.4 to 10.6; p = 0.98).Sufficiency was often supplementation-related (9/14, 64.3%). No associations were found with flares, treatment, season, or ocular complications.

Conclusions: In this selected cohort, vitamin D deficiency was common, but prevalence cannot be compared with the general pediatric population. Lower unadjusted 25(OH)D in idiopathic uveitis appeared age-related, although the wide adjusted confidence interval leaves uncertainty. Future studies should systematically document 25(OH)D, age, season, supplementation, and relevant lifestyle factors.