Multivitamin Intake During Pregnancy Reduces Risk of Autism Spectrum Disorder in Children

by | May 1, 2018 | 2018, Autism, Brain Health, Pregnancy and Lactation, Vitamins

Written by Angeline A. De Leon, Staff Writer. This perspective study finds that while moderate supplementation of multivitamins during pregnancy offers the greatest risk reduction for autism spectrum disorder in offspring, deficient or excessive supplementation of multivitamins during pregnancy significantly increases the risk.

women's healthAutism Spectrum Disorder (ASD) represents a group of neurodevelopmental disorders which affect behavior and social communication and are often characterized by life-long impairment in social functioning. Recent work suggests that ASD occurs in about one per 68 individuals in the U.S., a prevalence rate much higher than initially estimated by previous studies 1. While the etiology of ASD, like every disease/condition, involves a complex interaction between genetic and environmental factors, research has pinpointed a specific role for maternal intake of folate (folic acid) in the development of ASD. An essential B vitamin, folate critically influences gene expression and DNA repair 2, and studies show that adequate supplementation with folic acid during pregnancy (400 µg/d, based on U.S. Public Health guidelines) can significantly reduce the risk of birth defects in children 3. Following the mandatory fortification of grain products in the U.S. in 1998 4, serum folate levels have more than doubled across the general population 5, however, recent evidence shows that for most Americans, folic acid remains unmetabolized in the blood stream 6. Furthermore, in relation to ASD risk, the association between maternal intake of folate and ASD development is poorly understood. Preliminary studies suggest that prenatal supplementation with a multivitamin, which includes folic acid, may have a protective effect against ASD, but evidence based on biomarker data is needed to confirm such a relationship 7. Therefore, in a study 8 published in Pediatric and Perinatal Epidemiology (2018), researchers examined the effects of maternal multivitamin intake and plasma levels of folate and B12 (another essential B vitamin critical for brain development) on ASD risk in offspring.

A total of 1,257 mother-child pairs were recruited at the time of birth and prospectively followed through childhood. At 24-72 hours postpartum, maternal blood samples were collected and analyzed for plasma folate, B12, and homocysteine levels, and mothers completed a questionnaire interview assessing multivitamin supplementation (on a weekly basis). Based on electronic medical records, children who carried a diagnosis of autism, Asperger syndrome, and/or pervasive developmental disorder not otherwise specified were identified as having ASD.

Across all three trimesters of pregnancy, moderate multivitamin supplementation (3-5 times per week) was found to be associated with reduced risk of ASD. In comparison to moderate supplementation, both low (2 or fewer times per week) and high (greater than 5 times per week) multivitamin intake were associated with higher risk of ASD [First Trimester: Adjusted Hazard Ratio for Low Intake = 3.4, adjusted HR for High = 2.3; Second Trimester: adjusted HR for Low = 3.8, adjusted HR for High = 2.1; Third Trimester: adjusted HR for Low = 3.5, adjusted HR for High = 2.1]. Mothers with plasma folate levels in the highest 10th percentile (60.3 nmol/L or greater), when compared with the middle 80th percentile, showed a significantly increased risk of ASD in their offspring (adjusted HR = 2.5). Similarly, mothers with plasma B12 levels in the top 10th percentile (536.8 pmol/L or greater), when compared to the middle 80%, had about a 2.5 increased risk of ASD.

Evidence from this prospective study indicates that while moderate intake of multivitamins during pregnancy is optimal for reducing risk of ASD in children, both deficient and excessive nutrient supplementation can significantly increase risk. Results also indicate that elevated levels of plasma folate and B12 at the time of birth may elevate risk of ASD. Further studies are needed to replicate findings and identify optimum levels of folate and B12 for fetal neurodevelopment. 

Source: Raghavan R, Wiley AW, Volk H, et al. Maternal multivitamin intake, plasma folate and vitamin B12 levels and autism spectrum disorder risk in offspring. Pediatric and Perinatal Epidemiology. 2018; 32: 100-111. DOI: 10.1111/ppe.12414.

© 2017 John Wiley & Sons Ltd

Posted May 1, 2018.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

References:

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