Abstract: Objective To investigate the relationship between autism spectrum disorders and blood levels of Vitamin D and water-soluble vitamins.Methods A total of 71 children with autism spectrum disorder who attended the outpatient clinic of the Children's Rehabilitation Department of our hospital and received rehabilitation training from January to December 2019 were recruited as ASD group. Age-and gender matched children undergoing routine physical examination in our hospital were recruited as control group. Their serum 25(OH)D3 level was determined by chemiluminescence method. The concentration of water-soluble vitamins in blood was determined by ultra high performance liquid chromatography-tandem mass spectrometry.Results The blood levels of 25(OH)D3, Vitamin B1, Vitamin B5, Vitamin B6, and Vitamin B9 in children with ASD were lower than those in the control group(P＜0.05). No statistical difference was observed in Vitamin B2, Vitamin B3, Vitamin B7, Vitamin B12 or Vitamin C between the two groups(P>0.05). There were statistical differences in Vitamin B5, Vitamin B6, and Vitamin B9 in the blood of ASD children with different Vitamin D levels(P＜0.05), but no statistical difference in Vitamin B1 levels(P>0.05). The level of Vitamin D was significantly positively correlated with Vitamin B9(P＜0.05). No statistical correlation was observed between Vitamin D and Vitamin B1, Vitamin B5 or Vitamin B6(P>0.05).Conclusion The blood levels of Vitamin D, Vitamin B1, Vitamin B5, Vitamin B6 and Vitamin B9 in children with autism spectrum disorder are reduced. The levels of Vitamin B5, Vitamin B6, and Vitamin B9 are different in children with autism spectrum disorder with different levels of Vitamin D, and there is a significant positive correlation between the level of Vitamin D in the blood and the level of Vitamin B9. These results suggest that the children with autism spectrum disorder should have their levels of Vitamin D and water-soluble Vitamins monitored and take some vitamins according to the condition.

Key words: Autism spectrum disorder, Vitamin , Water-soluble vitamins