Vitamin D dynamics predict treatment response to intravenous glucocorticoids in thyroid-associated ophthalmopathy: a retrospective cohort study

Background Intravenous glucocorticoids (IVGC) represent first-line therapy for active moderate-to-severe thyroid-associated ophthalmopathy (TAO). The relationship between vitamin D (VitD) and IVGC efficacy in TAO remains undefined. Methods This retrospective study grouped TAO patients completing IVGC therapy with standardized VitD/calcium supplementation at First Affiliated Hospital of Xi’an Jiaotong University (2015–2019). Serum 25-hydroxyvitamin D (25(OH)D) and bone markers were measured pre/post-treatment. Multivariate regression and ROC analysis identified predictors. Results In total, 52 TAO patients were enrolled, including 33 responders and 19 non-responders. Non-responders had significantly higher baseline triglycerides, thyroxine and longer duration of ophthalmopathy. Responders exhibited higher baseline β-CTX and N-MID OC. Notably, 73.08% of patients had baseline 25(OH)D deficiency (