Prenatal Vitamin D, Multivitamin, and Folic Acid Supplementation and Brain Structure in Children with ADHD and ASD Traits: The Generation R Study

Background/Objectives: Maternal vitamin supplementation (including folic acid, vitamin D, and multivitamin supplements) during pregnancy may lower the likelihood of neurodevelopmental disorders in offspring. This study examines the associations between maternal vitamin suppletion during pregnancy and morphological patterns in offsprings’ brain structure and traits of Autism Spectrum Disorder (ASD) and Attention-Deficit Hyperactivity Disorder (ADHD) in a large population-based study of child development. Methods: The study cohort included a total of 3937 children (aged 9–11) participating in the Generation R cohort in Rotterdam, the Netherlands. Maternal vitamin D and folateserum levels, multivitamin supplement use, and overall dietary quality (as assessed by the Food Frequency Questionnaire, FFQ) during pregnancy were used as predictors. T1 structural MRI scans were acquired and segmented using Freesurfer to assess brain morphometry. Cortical and subcortical brain volumes of children were separated into four independent components and used as mediators. ADHD and ASD traits, as measured by parent-completed questionnaires (Child Behavior CheckList and Social Responsiveness Scale, respectively) were used as outcome variables. Results: Results show that (1) maternal vitamin D, multivitamin supplementation, and better diet quality were associated with fewer ADHD or ASD traits in the offspring; (2) vitamin D and diet quality were associated with larger-volume childhood brain components; (3) larger-volume brain components were associated with fewer ADHD and ASD traits; (4) part of the association between dietary factors in pregnancy and offspring ADHD and ASD traits was mediated through the brain volumes of the children. Conclusions: Though all observed effect sizes were small, further population-based research should be performed to further delineate the effects of gestational multivitamin and vitamin D exposure and investigate whether this may be an avenue for preventive interventions.