Association Between Vitamins Related to Brain Development and Sleep in Children with Autism Spectrum Disorders.

Purpose: Sleep problems and nutritional abnormalities are common in children with autism spectrum disorder (ASD), yet the relationships between specific vitamin status, sleep characteristics, and ASD symptoms remain unclear. This study investigated the associations between neurodevelopment-related vitamin levels, sleep problems, and clinical features in children with ASD. Patients and Methods: This cross-sectional study included 605 children with ASD aged 2-7 years. Blood vitamin levels were measured using high-performance liquid chromatography-tandem mass spectrometry. Sleep problems were assessed using the Children's Sleep Habits Questionnaire (CSHQ) and ASD symptoms were evaluated using the Social Responsiveness Scale (SRS), Childhood Autism Rating Scale (CARS), and Autism Diagnostic Observation Schedule-Second Edition (ADOS-2). Results: Vitamin A (VA) deficiency was the most prominent nutritional abnormality, followed by vitamin D (VD) deficiency. VA levels differed significantly by sex, whereas VD levels varied across age groups. Several dimensions of sleep problems showed significant differences according to both sex and age. Lower VA levels were associated with greater sleep problems, including higher bedtime resistance, daytime sleepiness, and higher total CSHQ scores (all P < 0.05). Lower VD levels were associated with greater severity of core ASD symptoms (all P < 0.05), but not with sleep problems. Greater sleep problems were consistently associated with more severe ASD symptoms. Conclusions: VA and VD deficiencies are prevalent among children with ASD. VA levels were associated with sleep problems, whereas VD status was associated with ASD symptom severity. These findings suggest that nutritional status may be associated with specific clinical features of ASD and warrant further investigation in longitudinal studies.