Objective: To investigate serum vitamin A and vitamin D status in children aged 2-<7 years in 20 cities in China. Methods: A cross-sectional study was conducted. A total of 2 924 healthy children aged 2-<7 years were recruited from September 2018 to September 2019 from 20 cities in China, categorized by age groups of 2-<3 years, 3-<5 years, and 5-<7 years. The demographic and economic characteristics and health-related information of the enrolled children were investigated. Body weight and height were measured by professional staff members. The serum vitamin A and vitamin D levels were detected by high-performance liquid chromatography-tandem mass spectrometry. Chi-square test and Logistic regression were applied to analyze the association between vitamin A and vitamin D deficiency and insufficiency as well as their underlying impact factors. Results: The age of the 2 924 enrolled children was 4.33 (3.42, 5.17) years. There were 1 726 males (59.03%) and 1 198 females (40.97%). The prevalences of vitamin A and vitamin D deficiency in enrolled children were 2.19% (64/2 924) and 3.52% (103/2 924), respectively, and the insufficiency rates were 29.27% (856/2 924) and 22.20% (649/2 924), respectively. Children with both vitamin A and vitamin D deficiencies or insufficiencies were found in 10.50% (307/2 924) of cases. Both vitamin A (χ2=7.91 and 8.06, both P=0.005) and vitamin D (χ2=71.35 and 115.10, both P<0.001) insufficiency rates were higher in children aged 3-<5 and 5-<7 years than those in children aged 2-<3 years. Vitamin A and vitamin D supplementation in the last 3 months was a protective factor for vitamin A and D deficiency and insufficiency, respectively (OR=0.68 and 0.22, 95%CI 0.49-0.95 and 0.13-0.40, both P<0.05). The rates of vitamin A and D insufficiency was higher in children with annual household incomes <60 000 RMB than in those with annual household incomes ≥60 000 RMB (χ2=34.11 and 10.43, both P<0.01). Northwest and Southwest had the highest rates of vitamin A and vitamin D insufficiency in children aged 2-<7 yeas, respectively (χ2=93.22 and 202.54, both P<0.001). Conclusions: Among 20 cities in China, children aged 2-<7 years experience high rates of vitamin A and vitamin D insufficiency, which are affected by age, family economic level, vitamin A and vitamin D supplementation, and regional economic level. The current results suggest that high level of attention should be paid to vitamin A and vitamin D nutritional status of preschool children.
目的： 调查我国20个城市2~<7岁儿童血清维生素A和维生素D水平。 方法： 横断面研究，2018年9月至2019年9月在中国20个城市中共招募2 924名2~<7岁健康儿童，按年龄分为2~<3岁、3~<5岁和5~<7岁组。对入组儿童进行人口经济学特征及相关健康知识问卷调查，测定儿童体重和身高，采用高效液相色谱-串联质谱法检测儿童血清维生素A、D水平。采用χ2检验和多因素Logistic回归分析维生素A、D缺乏和不足的影响因素。 结果： 2 924名儿童年龄4.33（3.42，5.17）岁，男1 726名（59.03%）、女1 198名（40.97%）。总体儿童维生素A、D缺乏率分别为2.19%（64/2 924）和3.52%（103/2 924），不足率分别为29.27%（856/2 924）和22.20%（649/2 924）。10.50%（307/2 924）的儿童维生素A、D均不充足。3~<5岁和5~<7岁组儿童维生素A（χ2=7.91、8.06，均P=0.005）、维生素D（χ2=71.35、115.10，均P<0.001）不足率均高于2~<3岁组儿童。近3个月补充维生素A、D分别是维生素A、D不充足的保护因素（OR=0.68、0.22，95%CI 0.49~0.95、0.13~0.40，均P<0.05）。家庭年收入<6万元的儿童中维生素A、D不足率显著高于家庭年收入≥6万元的儿童（χ2=34.11、10.43，均P<0.01）；西北和西南分别为2~<7岁维生素A和维生素D不足率最高的地区（χ2=93.22、202.54，均P<0.001）。 结论： 我国20个城市中2~<7岁儿童维生素A、D不足率均较高。年龄、家庭经济水平、近期补充以及地区经济水平等因素均可影响维生素A、D营养状况。应高度关注学龄前儿童的维生素A、D营养状况。.