Vitamin D nutritional status and related factors in primary and secondary school students in Yinchuan

Abstract

Objective To understand the vitamin D nutritional status and associated factors of children and adolescents aged 6-18 in Yinchuan, so as to provide theoretical basis for improving the vitamin D malnutrition status of children and adolescents.

Methods Using stratified cluster sampling method, 1 615 children and adolescents from 36 classes in 2 primary schools, junior high schools and high schools were randomly selected from Yinchuan, Ningxia. Venous blood sampling, physical examinations and questionnaires were conducted.

Results The vitamin D deficiency rate and appropriate rate for students were 66.9% and 33.1%, respectively. There was a statistically significant difference in vitamin D deficiency among different age groups (χ ² = 25.65, P<0.05). The 6-year-old group had the highest (79.2%), followed by the 13-year-old group (76.6%), and the 12-year-old group (75.3%). The results of binary Logistic regression showed that the factors influencing the vitamin D nutritional status of children and adolescents included age ( OR = 0.95), daily outdoor exercise time ( OR = 0.49), exclusive breastfeeding ( OR = 0.63) and mother' s education ( OR = 0.73, 0.43). The decision tree QUEST and Logistic regression combination model results show that the key factors affecting vitamin D nutrition status include daily outdoor exercise time, age, mother’ s education, BMI, and interaction between outdoor exercise time and age, interaction between outdoor exercise time and mother’ s education, interaction between age and mother’ s education, interaction between exclusive breastfeeding and BMI.

Conclusion The detection rate of vitamin D deficiency in children and adolescents aged 6-18 in Yinchuan is high, factors associated with vitamin D nutritional status includes daily outdoor exercise time, age, mother’ s education, BMI, and interaction between outdoor exercise time and age, interaction between outdoor exercise time and mother’ s education, interaction between age and mother’ s education, interaction between exclusive breastfeeding and BMI.

Abstract

【摘要】 目的 了解银川 6 〜 18 岁儿童青少年的维生素D营养状况及其影响因素, 为改善儿童青少年维生素D营养 状况提供理论依据。 方法 采用分层整群随机抽样方法, 从银川市抽取小学、初中、高中各 2 所共 36 个班1 615名学生作 为调查对象, 进行静脉采血、体格检查和问卷调查。 结果 学生维生素D缺乏率和适宜率分别为66.9%和33.1%, 不同年 龄组间维生素D缺乏率差异有统计学意义( χ ² = 25.65, P<0.05), 6岁组最高 (79.2%), 其次为 13 岁组 (76.6%)和 12 岁组 (75.3%)。二元Logistic回归分析结果显示, 影响儿童青少年维生素D营养状况的因素有年龄 ( OR = 0.95)、每日户外运动 时间 ( OR = 0.49)、纯母乳喂养 ( OR = 0.63)和母亲学历 (高中及大专、本科及以上的 OR值分别为0.73, 0.43);决策树QUEST 和Logistic回归组合模型结果显示, 影响儿童青少年维生素D营养状况的关键因素有每日户外运动时间、年龄、母亲学历、体质量指数 (BMI)以及户外运动时间和年龄、户外运动时间和母亲学历、年龄和母亲学历、纯母乳喂养和BMI之间的交互 作用。 结论 银川学生维生素D营养状况不良检出率较高, 影响维生素D营养状况的关键因素有每日户外运动时间、年 龄、母亲学历、BMI以及户外运动时间和年龄、户外运动时间和母亲学历、年龄和母亲学历、纯母乳喂养和BMI之间的交互 作用。