Phenotype-specific 25-hydroxyvitamin D and fat-soluble vitamin profiles in girls with pediatric endocrine disorders: a large cross-sectional study.

OBJECTIVE: To characterize serum vitamin A, total 25-hydroxyvitamin D [25(OH)D] and vitamin E across common pediatric endocrine disorders in girls and to test whether the profiles are phenotype-specific. METHODS: In this single-center retrospective cross-sectional study, serum vitamin A, total 25(OH)D, and vitamin E were simultaneously measured by high-performance liquid chromatography in 4,111 girls aged 3-13 years, including healthy controls (n = 1,503), central precocious puberty (CPP; n = 1,146), short stature (n = 970), and obesity (n = 492). Age-adjusted effect sizes, logistic regression, restricted cubic spline analysis, and pre-specified sensitivity analyses were performed. RESULTS: Each phenotype demonstrated a distinct fat-soluble vitamin profile. Obesity was characterized by higher vitamin A (adjusted Cohen's d = +0.50) and lower 25(OH)D (d = -0.16), whereas CPP showed lower 25(OH)D (d = -0.26) and lower vitamin E (d = -0.25). In contrast, short stature was associated with higher 25(OH)D (d = +0.26). Vitamin D deficiency was more common in CPP (OR 1.43, 95% CI 1.20-1.70) but less common in short stature (OR 0.60, 95% CI 0.48-0.74). Restricted cubic spline analysis demonstrated a significant nonlinear inverse association between continuous 25(OH)D concentrations and CPP. The higher 25(OH)D concentrations observed in short stature persisted after excluding participants positive for the vitamin D2 supplementation marker. CONCLUSION: In girls, common pediatric endocrine disorders carry distinct, phenotype-specific fat-soluble vitamin profiles, with CPP and short stature diverging in opposite directions for vitamin D. Effect sizes were modest, and the short-stature elevation may substantially reflect unmeasured cholecalciferol supplementation; these group-level patterns therefore warrant cautious, biomarker-oriented interpretation.