Vitamin D status in pre-school children in rural Nepal

Objective: Vitamin D plays a major role in Ca and bone metabolism, and its extraskeletal functions are being appraised. Although inadequate vitamin D concentrations have been reported in populations worldwide, too little is known about vitamin D status and its determinants among children in developing countries. We aimed to determine vitamin D status and its determinants in Nepalese children of pre-school age. Design: A community-based, cross-sectional study. Setting: Rural Nepal at latitude 27.39 degrees N. Subjects: Healthy children (n 280) aged 12-60 months, selected randomly from the records of a vitamin A supplementation programme. Blood samples were collected using the dried blood spot technique and analysed for serum 25-hydroxyvitamin D (s-25(OH)D) concentration using liquid chromatographytandem mass spectrometry. Ca intake and background variables were assessed with a structured questionnaire. Results: Hypovitaminosis D, defined as s-25(OH) D concentration less than 50 nmol/l, was found in 91.1 % of the children. S-25(OH) D concentration was not related to gender, socio-economic indicators, sun exposure or nutritional status. Currently breast-fed children had higher s-25(OH) D concentrations (36.4 (SD 13.2) nmol/l) than those who were not (28.6 (SD 9.8) nmol/l, P<0.001). Adjustment for sociodemographic factors did not alter the results. Conclusion: There is widespread vitamin D deficiency among pre-school children in a rural area of Nepal. In our sample, sociodemographic factors did not affect the vitamin D status of children, but prolonged breast-feeding was associated with higher s-25(OH) D concentrations. Further research is required to investigate the health consequences of poor vitamin D status for this population.