OBJECTIVETo examine serum 25-hydroxyvitamin D levels in children with tic disorders (TD) and to explore the relationship between vitamin D level and TD.

METHODSOne hundred and thirty-two children who were diagnosed with TD between November 2016 and May 2017 were enrolled as the TD group, including 8 cases of Tourette syndrome, 32 cases of chronic TD, and 92 cases of transient TD. One hundred and forty-four healthy children served as the control group. Peripheral venous blood samples were collected from each child. Serum levels of 25-hydroxyvitamin D were measured using HPLC-MS/MS. The categories of vitamin D status based on serum 25-hydroxyvitamin D level included: normal (>30 ng/mL), insufficiency (10-30 ng/mL) and deficiency (<10 ng/mL).

RESULTSMean serum level of 25-hydroxyvitamin D in the TD group was significantly lower than that in the control group (P<0.01). The rate of vitamin D insufficiency or deficiency in the TD group was significantly higher than in the control group (P<0.01). Mean serum level of 25-hydroxyvitamin D in the transient tic group was higher than in the TS group (P<0.05).

CONCLUSIONSVitamin D insufficiency or deficiency might be associated with the development of TD, and the level of serum 25-hydroxyvitamin D might be related to the classification of TD.