Vitamin D status and predictors of hypovitaminosis D in internationally adopted children

962 internationally adopted children (median age: 5.47 years; IQR:3.14-7.93) were included in the study. Median 25(OH)D level was 22.0 ng/mL (IQR:15.0-30.0 ng/mL); 710/962 (73.8%) children showed hypovitaminosis D (<30 ng/mL), 388/962 (40.3%) had vitamin D deficiency (<20 ng/dL), and 92/962 (9.6%) had severe vitamin D deficiency (<10ng/mL). No case of clinical rickets was observed. Hypovitaminosis D was particularly frequent (>90%) in children adopted from Ethiopia, Peru, India, Bulgaria and Lithuania. At multivariate analysis an increased risk of hypovitaminosis D was found to be associated with: age ≥ 6 years, time spent in Italy ≥ 3 months, blood sample taken in winter, spring or fall, compared to summer. Gender, ethnicity/continent of origin, tubercular infection, intestinal parassitosis and BMI-z-score < -2 were not associated with vitamin D status. CONCLUSION: Hypovitaminosis D is common in internationally adopted children