2015—2017年陕西省农村中小学生维生素D营养状况分析

目的 了解陕西省农村地区中小学生维生素D营养状况,评估国家“农村义务教育学生营养改善计划”(简称“计划”)的实施效果,为合理补充维生素D提供科学依据。 方法 采用多阶段分层整群抽样,抽取2015—2017年陕西省参加“计划”的横山区、长武县、勉县中小学学生,采集空腹静脉血,对血清25-羟基维生素D(25-hydroxyvitamin D,25-(OH)D)进行测量,计算维生素D缺乏率、亚临床缺乏率,并进行分析评价。 结果 2015—2017年监测学生血清25-(OH)D为(22.21±9.04)ng/ml,维生素D缺乏率、亚临床缺乏率分别为4.39%,41.95%;男生和女生血清25-(OH)D平均水平为(23.42±9.32)ng/ml和(20.94±8.56)ng/ml,差异有统计学意义(t=7.537,P＜0.001),小学生高于初中生(t=15.644,P＜0.001),陕北＞关中＞陕南(F=90.810,P＜0.001);维生素D缺乏率、亚临床缺乏率,女生＞男生(χ²=47.665,P＜0.001),初中生＞小学生(χ²=146.965,P＜0.001),陕南＞关中＞陕北(χ²=219.214,P＜0.001),2015年、2016年＞2017年(χ²=382.476,P＜0.001)。结论 自“计划”实施以来,学生维生素D营养缺乏有所改善,但仍不容乐观,仍有部分处于亚临床缺乏状态,应引起重视,加大营养改善力度。

Nutritional status of vitamin D in primary and middle school students in rural areas of Shaanxi province, 2015-2017

Objective To investigate the nutritional status of vitamin D in middle school students and pupils in rural areas of Shaanxi province, to evaluate the implementation effectiveness of the Nutrition Improvement Program for Rural Compulsory Education Students (abbreviated to the program), and to provide a scientific basis for reasonable supplementation of vitamin D. Methods A multi-stage stratified sampling method was used to select primary and middle school students who participated in the program in Hengshan district, Changwu county and Mian county of Shaanxi province in 2015-2017. Fasting venous blood samples were collected to detect serum level of 25-hydroxyvitamin D (25-(OH)D). The clinical and subclinical deficiency rates of vitamin D were analyzed. Results The overall serum level of 25-(OH)D in monitored school students from 2015 to 2017 was (22.21±9.04)ng/ml, and the clinical and subclinical deficiency rates of vitamin D were 4.39% and 41.95% respectively. The averagelevels of serum 25-(OH)D in males and females were (23.42±9.32)ng/ml and (20.94±8.56)ng/ml, respectively, showing statistically significant differences (t=7.537, P<0.001). The average level of serum 25-(OH)D was higher in pupils than in junior middle students (t=15.644, P<0.001), higher in northern Shaanxi than in Guanzhong and higher in Guanzhong than in southern Shaanxi (F=90.810, P<0.001). The clinical and subclinical deficiency rates of vitamin D were higher in females than in males (χ²=47.665, P<0.001), higher in junior middle school students than in pupils (χ²=146.965, P<0.001), higher in southern Shaanxi than in Guanzhong, higher in Guanzhong than in northern Shaanxi (χ²=219.214, P<0.001), and higher in 2015 or 2016 than in 2017 (χ²=382.476, P<0.001). Conclusions By and large, the nutritional status of vitamin D in the students has been improved since the program has been implemented, but it is still not very optimistic. There still exists subclinical deficiency of vitamin D in some students; and hence, special attention should be paid to correct the subclinical deficiency of vitamin D and improve the nutrition status.