Vitamin D Status in Irish Children and Adolescents: Value of Fortification and Supplementation

Background. Vitamin D has important skeletal and extraskeletal roles but those living at northerly latitudes are at risk of suboptimal levels because of reduced sunlight exposure. Aim. To describe the vitamin D status of Irish children and identify factors predictive of vitamin D status. Methods. A prospective cross sectional study was undertaken over a 12 month period. Two hundred and fifty two healthy children attending for minor medical or surgical procedures were recruited. All had 25-hydroxyvitamin D (25OHD), parathyroid hormone and bone profiles measured. Results. The mean (standard deviation) for 25OHD was 51(25) nmol/L (20.4 (10) ng/mL). Forty-five percent had levels >50 nmol/L (20 ng/mL). The following variables were significantly associated with 25OHD levels >50 nmol/L (20 ng/mL): sample drawn in April-September, use of vitamin D supplements, consumption of formula milk, and non-African ethnicity. Conclusion. More than half of the children in this study had 25OHD levels less than 50 nmol/L (20 ng/mL). Vitamin D status was significantly improved by augmented oral vitamin D intake.