RESUMEN
OBJECTIVES: To investigate the levels of serum folate and vitamin B12 (VB12) and their association with the level of neurodevelopment in preschool children with autism spectrum disorder (ASD). METHODS: A total of 324 ASD children aged 2-6 years and 318 healthy children aged 2-6 years were recruited. Serum levels of folate and VB12 were measured using chemiluminescent immunoassay. The Social Responsiveness Scale and the Childhood Autism Rating Scale were used to assess the core symptoms of ASD children, and the Gesell Developmental Schedule was employed to evaluate the level of neurodevelopment. RESULTS: The levels of serum folate and VB12 in ASD children were significantly lower than those in healthy children (P<0.05). Serum folate levels in ASD children were positively correlated with gross and fine motor developmental quotients (P<0.05), and serum VB12 levels were positively correlated with adaptive behavior, fine motor, and language developmental quotients (P<0.05). In ASD children aged 2 to <4 years, serum folate levels were positively correlated with developmental quotients in all domains (P<0.05), and serum VB12 levels were positively correlated with language developmental quotient (P<0.05). In male ASD children, serum VB12 levels were positively correlated with language and personal-social developmental quotients (P<0.05). CONCLUSIONS: Serum folate and VB12 levels in preschool ASD children are lower than those in healthy children and are associated with neurodevelopmental levels, especially in ASD children under 4 years of age. Therefore, maintaining normal serum folate and VB12 levels may be beneficial for the neurodevelopment of ASD children, especially in ASD children under 4 years of age.