Abstract: Background　In recent years，vitamin D has been reported to be possibly related to the onset of attention deficit hyperactivity disorder（ADHD）in studies.However，the results of different studies are not consistent，and there are few related systematic analyses.Objective　To analyze the relationship between ADHD and vitamin D level in children and teenagers.Methods　The databases of PubMed，EMBase，The Cochrane Library，CNKI，CBM，VIP and Wanfang Data Knowledge Service Platform were searched from inception to February 26，2019 to identify articles about the relationship of ADHD with vitamin D level in children and teenagers.The data，such as gender，age，serum 25-hydroxyitamin D（25（OH）D）levels，prevalence rates of insufficient or deficient serum 25（OH）D（defined as less than 30 μg/L），different serum 25（OH）D levels（< 10 μg/L，< 20 μg/L，10-30 μg/L，> 20 μg/L，>30 μg/L）were extracted from the included articles and the risk of bias was evaluated by two researchers，independently.Meta analysis was performed using RevMan 5.3 and Stata 12.0.Results　Finally，11 articles with 13 960 cases（2 305 cases of ADHD，and 11 655 healthy controls）were included.The results of meta-analysis showed that the mean serum 25（OH）D level in ADHD group was lower than that of healthy control group〔MD=-6.81，95%CI（-8.93，-4.69），P<0.000 01〕.The results of stratified analysis showed that the level of serum 25 （OH） D in ADHD group was lower than that in healthy control group （P< 0.000 01）.ADHD group showed higher prevalence rate of serum 25（OH）D <10 μg/L〔OR=-1.86，95%CI（1.53，2.26），P<0.000 01〕，lower prevalence rate of serum 25（OH）D>30 μg/L 〔OR=-0.20，95%CI（-0.31，-0.08），P=0.000 6〕，and higher prevalence rate of insufficient or deficient serum 25（OH）D level 〔OR=3.16，95%CI（1.75，5.73），P=0.000 1〕compared with the healthy control group.There were no statistically significant differences between the two groups in the prevalence rates of serum 25（OH）D ranged from 10 to 30 μg/L 〔OR=1.04，95%CI（0.90，1.22），P=0.58〕，serum 25（OH）D <20 μg/L〔OR=1.04，95%CI（0.50，2.18），P=0.92〕and serum 25（OH）D >20 μg/L〔OR=1.02，95%CI（0.44，2.37），P=0.97〕.ADHD group showed younger mean age〔OR=-0.37，95%CI（-0.71，-0.04），P=0.03〕，and higher male ratio compared with the healthy control group〔OR=2.24，95%CI（1.39，3.62），P=0.000 9〕.Conclusion　Children with ADHD had lower serum level of 25（OH）D than healthy children generally.ADHD group had higher prevalence rate of serum 25（OH）D level of 10 μg/L or 30 μg/L，but similar prevalence rate of serum 25（OH）D level of 20 μg/L compared with the control group.

Key words: Attention deficit disorder with hyperactivity, Vitamin D, Children, Adolescents, Meta-analysis, Systematic review

摘要： 背景　近年来国内外研究发现维生素D与注意缺陷多动障碍（ADHD）发病可能相关，但不同研究结果间存在差异，且相关系统分析研究较少。目的　分析儿童ADHD与不同维生素D水平的关系。方法　检索PubMed、EMBase、The Cochrane Library、中国知网、中国生物医学文献数据库、维普网、万方数据知识服务平台，检索时间为建库至2019-02-26。2名研究者独立提取纳入文献中患儿的性别、年龄、血清25羟维生素D〔25（OH）D〕水平、血清25（OH）D不足或缺乏率（以30 μg/L为界值）、不同血清25（OH）D水平（<10 μg/L、<20 μg/L、10~30 μg/L、>20 μg/L、>30 μg/L）的发生率等资料并评价文献偏倚风险。采用RevMan 5.3以及Stata 12.0软件进行Meta分析。结果　共纳入11篇文献，13 960例研究对象，其中ADHD组2 305例，健康对照组11 655例。Meta分析结果显示，ADHD组血清25（OH）D水平低于健康对照组〔MD=-6.81，95%CI（-8.93，-4.69），P<0.000 01〕，进一步对国家地区分层分析结果显示，不同国家ADHD组血清25（OH）D水平低于健康对照组（P<0.000 01）。ADHD组血清25（OH）D水平<10 μg/L的发生率高于健康对照组〔OR=-1.86，95%CI（1.53，2.26），P<0.000 01〕，>30 μg/L的发生率低于健康对照组〔OR=-0.20，95%CI（-0.31，-0.08），P=0.000 6〕，不足或缺乏率（以30 μg/L为界值）高于健康对照组〔OR=3.16，95%CI（1.75，5.73），P=0.000 1〕；两组间血清25（OH）D水平10~30 μg/L〔OR=1.04，95%CI（0.90，1.22），P=0.58〕、<20 μg/L〔OR=1.04，95%CI（0.50，2.18），P=0.92〕、>20 μg/L〔OR=1.02，95%CI（0.44，2.37），P=0.97〕发生率比较，差异均无统计学意义。ADHD组患儿年龄小于健康对照组〔OR=-0.37，95%CI（-0.71，-0.04），P=0.03〕，男性儿童青少年所占比例高于健康对照组〔OR=2.24，95%CI（1.39，3.62），P=0.000 9〕。结论　ADHD患儿的血清25（OH）D水平较健康儿童低。当血清25（OH）D水平以10 μg/L或30 μg/L进行划分时，ADHD患儿血清25（OH）D不足或缺乏率高于健康儿童；当以20 μg/L进行划分时，ADHD患儿血清25（OH）D水平与健康儿童无差异。

关键词: 注意缺陷多动障碍, 维生素D, 儿童, 青少年, Meta分析, 系统评价