Vitamin D status and site-specific fracture pattern associations in older adults with fragility fractures: a cross-sectional analysis of 2543 patients

Background Vitamin D deficiency is an established risk factor for osteoporosis and fragility fractures in the elderly. However, its prevalence and association with specific anatomic fracture sites remain incompletely understood. This study aimed to assess vitamin D status and investigate its variation across fracture sites in elderly patients with fragility fractures. Methods A total of 2543 hospitalized patients aged ≥60 years with fragility fractures were included. Serum 25(OH)D concentrations were measured by liquid chromatography–tandem mass spectrometry. Demographic characteristics, admission indications, and comorbidities were extracted from electronic medical records to assess the prevalence of vitamin D deficiency and identify associated risk factors. A generalized linear model with a gamma distribution was used to analyze the association between serum 25(OH)D concentration and fracture site, adjusting for age, sex, sampling season, and comorbidities. Results Overall, 35.9% of patients were vitamin D deficient (