Nutrient Status of Vitamin D among Chinese Children

BACKGROUND Vitamin D deficiency is considered to be a public health problem. However, the nutrient status of vitamin D in Chinese children is unclear. The aim of this study was to describe the vitamin D status among children aged under 18 years in southeast China. METHODS Children who visited the Huzhou Maternal and Child Care Hospital from January 2012 to August 2015 were included in this large cross-sectional study. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by electrochemiluminescence immunoassay. Vitamin D status was defined as deficiency (25(OH)D < 20 ng/mL), insufficiency (25(OH)D: 20-29 ng/mL) and sufficiency (25(OH)D ≥ 30 ng/mL). The association between relevant variables and vitamin D status was analyzed by a using generalized estimated equation model and a multivariate regression model. RESULTS 13,997 children aged under 18 years were included. Of these, 23.3% children suffered from low vitamin D status (deficiency and insufficiency), while 76.7% had a sufficient vitamin D status. The prevalence of low vitamin D status was 29.7% in winter and 23.4% in spring, which was higher than that in summer (21.4%) and autumn (19.9%). Clinical visiting children (32.1%) suffered more from low vitamin D than health examination children (17.6%). Additionally, age and season were independently and significantly associated with 25(OH)D concentrations, respectively. CONCLUSIONS The deficiency and insufficiency status of vitamin D was very common among newborns and children aged one to 17 years. This indicates that more sunshine and vitamin D-fortified foods are necessary among Chinese children.