Correlation between vitamin D and folic acid levels and the severity of autism spectrum disorder in children

Objective To analyze the correlation between vitamin D(VitD) and folic acid levels and the severity of autism spectrum disorder (ASD) in children.Methods A total of 55 children who were admitted to Rugao People's Hospital from March 2017 to March 2022 and diagnosed with ASD were selected as an ASD group. Meanwhile, another 55 healthy children who underwent physical examination in our hospital during the same period were selected as a control group. Their fasting blood samples were collected from the peripheral veins in the morning to detect the levels of serum 25(OH)D₃ and folic acid levels. The severity of ASD in these children was assessed using the Children's Autism Rating Scale (CARS). Pearson correlation analysis was conducted to analyze the relationship between serum 25(OH)D₃ and folic acid and CARS scores in ASD children. A receiver operating characteristic curve was plotted to analyze the relationship between serum 25(OH)D₃ and the severity of ASD children.Results The levels of serum 25(OH)D₃ and folic acid in the ASD group were significantly lower than those in the control group (all P<0.05). In addition, there were statistical differences in VitD deficiency rate and folate deficiency rate between the two groups (P<0.05). According to the CARS, there were 19 severe cases and 36 mild to moderate cases among the 55 ASD children. The VitD deficiency rate in severe children was significantly higher than that in mild to moderate children (P<0.05). Pearson correlation analysis showed that there was a strong negative correlation between 25(OH)D₃ and CARS scores (r=-0.606, P=0.000). ROC curve analysis showed that when 25(OH)D₃ was 15.8 μg/L (the optimal cut-off value), the sensitivity and specificity of severe ASD children were 73.80% and 91.4%, respectively, with the area under the curve of 0.85.Conclusions Serum 25(OH) D₃ and folic acid levels in ASD children are significantly reduced. ASD is correlated with VitD. 25(OH) D₃ can be used as an auxiliary indicator to predict the severity of children with severe ASD.