Abstract: Objective  To evaluate and analyze the clinical relationship between tic disorder in children and Vitamin D(VitD) status. Methods  Relevant Chinese and English literature from CNKI,  Wanfang database,  VIP database,  Cochrane Library,  PubMed and EMbase were all searched from the establishment of the database to August 2020. Two researchers independently extracted the included literature data and evaluated the risk of literature bias. RevMan5.3 software was used for Metaanalysis. Results  Finally, four literatures were included for Meta analysis, with a total of 1  043 cases,  including 620 cases in TD group and 423 cases in healthy control group. This study showed that the average level of serum 25 hydroxyl VitD in the TD group was lower than that in the healthy control group（MD=-5.24，95%CI：-9.75-0.72，P<0.02）. Subgroup analysis showed that there was no statistically significant differences in serum VitD levels between TTD and CTD groups（MD=1.55，95%CI：-2.435.53，P<0.45）.There was no significant difference in serum VitD levels between CTD group and TS group（MD=1.06，95%CI：-0.082.21，P=0.07）.There was no significant difference in serum VitD between TTD group and TS group（MD=3.47，95%CI：-1.168.10，P=0.14）. Four literatures showed that there was no statistical difference in male children between TD group and healthy group (OR=1.36,  95%CI: 0.802.32,  P=0.25). There was no statistically significant difference in the age of children between TD group and healthy group(OR=0.03,  95%CI: -0.330.39,  P=0.86). Conclusion  This metaanalysis showed that the serum 25 hydroxyl VitD level of TD children was lower than that of healthy children, with no difference among the subgroups.

Key words: tic disorder, Vitamin D, children