关键词: 25羟维生素D, 维生素D缺乏和不足, 维生素D补充, 阳光暴露, 儿童

Abstract: Objective To investigate the serum 25-hydroxyvitamin D[(25-(OH)D]in children aged 2~6 years in urban of Xi′an in summer, and to analyze related factors, in order to strengthen attention of late vitamin D(VD) deficiency and insufficiency. Methods A total of 615 children who took physical examination in Xi′an Maternal and Child Health Hospital from July to September 2017 were enrolled in this study.Self-designed questionnaires were filled out by parents under informed consents.3 ml of limosis vein blood was collected and the serum VD was measured by liquid chromatography tandem mass spectrometer made in Co.AB,USA(API4000).Finally 471 questionnaires were received. Results The average level of 25-(OH)D in 615 children was (32.81±7.93) ng/ml.The rate of abnormal VD level(including VD deficiency and VD insufficiency) was 38.9% (239/615), which was statistically higher than that of southern China(χ²=14.65,P＜0.001),but was not significantly different from those of Toronto, Canada and northern China(χ²=1.79,2.45,P＞0.05).The rate of VD deficiency was statistically lower than that of South Carolina, US(χ²=14.2,P＜0.001).There was no significant differences on outdoor time among VD deficiency group, VD insufficiency group, VD sufficiency group and desired level of VD group(F=0.784,P=0.503).Children in desired level of VD group took VD more frequently than other three groups(P＜0.001). Conclusions VD is at low level of normal interval in children aged 2-6 years in urban area of Xi′an in summer, and VD deficiency and insufficiency is common in such population.So proper outdoor time and VD supplementation will help to facilitate children′s growth.

Key words: 25-hydroxyvita D, vitamin D insufficiency and deficiency, vitamin D supplementation, sunlight explosion, children