Rachitic Changes, Demineralization, and Fracture Risk in Healthy Infants and Toddlers with Vitamin D Deficiency

Purpose: To examine radiographic findings in children with vitamin D deficiency in comparison with biochemical marker levels and prevalence of fractures. Materials and Methods: The parents or guardians of all participants provided written informed consent at the time of enrollment. The institutional review board approved the protocol, and HIPAA guidelines were followed. From a prospective sample of children seen for routine clinical care, 40 children with vitamin D deficiency (25-hydroxyvitamin D [25-OHD] level, <20 ng/mL) were identified, and high-detail computed radiographs of the wrists and knees were obtained. The children ranged in age from 8 to 24 months. Radiographs were scored by three readers with use of the 10-point Thacher score for rachitic changes and a five-point scale for demineralization. Serum calcium, phosphorus, alkaline phosphatase, and parathyroid hormone levels were determined. Fracture history was obtained for 35 of the 40 patients (88%). Results: All readers identified rachitic changes at both readings in two patients (5%) and demineralization in two patients (5%). Interrater agreement was 65% for rachitic changes (kappa = 0.33) and 70% for demineralization (kappa = 0.37). When the majority of the raters determined that rachitic changes were absent at both readings, alkaline phosphatase levels were lower than those with other assessments (median, 267 vs 515 U/L [4.4589 vs 8.6005 mu kat/L]; P = .01). When most raters determined that demineralization was present at both readings, serum 25-OHD levels were lower than those at other assessments (median, 9.0 vs 17.5 ng/mL [22.464 vs 43.68 nmol/L]; P = .02). No fractures were reported or identified radiographically. Conclusion: In infants and toddlers with vitamin D deficiency, rachitic changes and definite demineralization are uncommon and fracture risk is low. (C) RSNA, 2011