Correlation between serum vitamin D level and uterine volume in girls with idiopathic central precocious puberty

Objectives: Investigate serum vitamin D (vit D) levels' relation to uterine volume in idiopathic central precocious puberty (ICPP) girls and compare findings with normal peers.Methods: Analyzed 278 ICPP cases from January 2017 to September 2022 alongside 239 normally developing girls. Collected clinical data and lab markers and performed subgroup analysis based on vit D levels. Correlation and regression analyses were conducted.Results: The ICPP group exhibited elevated uterine volume and lower serum vit D compared to controls (p<0.05). A weak negative correlation was noted between vit D and uterine volume in ICPP (r=-0.193, p=0.004), and no such correlation in controls (r=-0.073, p=0.319). The ICPP vit D deficiency subgroup displayed higher uterine volume than the insufficiency and sufficiency subgroups (p<0.05). Uterine volume in the insufficiency subgroup exceeded the sufficiency subgroup (p<0.05). After adjusting for confounders, lower vit D is linked to increased ICPP uterine volume (non-standardized regression coefficient beta=-25.55, 95 % CI= -46.23, -4.87, p=0.016). A Limited correlation between vit D and uterine volume was seen in girls with normal pubertal timing.Conclusions: We demonstrated a correlation between vit D and uterine volume in ICPP girls, absent in normal peers. ICPP girls often exhibit lower vit D levels and increased uterine volume. Further research is vital for understanding vit D's role in ICPP pathogenesis and guiding prevention and treatment strategies.