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.