Higher maternal vitamin D levels in early pregnancy linked to improved child cognition

Higher maternal vitamin D levels in early pregnancy linked to improved child cognition | Image Credit: © bit24 - stock.adobe.com.

Higher vitamin D concentrations during pregnancy may be associated with improved cognitive performance in children, according to a study from the Environmental influences on Child Health Outcomes (ECHO) Cohort published in The American Journal of Clinical Nutrition.^1,2

The investigation included 912 mother–child pairs from 5 ECHO cohort sites across the United States. Maternal 25-hydroxyvitamin D [25(OH)D] concentrations were measured from blood samples collected between 4 and 42 weeks’ gestation, with a median collection time of 23 weeks. Cognitive outcomes were assessed when children were aged 7 to 12 years using the NIH Toolbox Cognition Battery, which evaluates composite scores for fluid cognition (problem-solving and novel information processing), crystallized cognition (knowledge-based skills such as vocabulary), and overall cognition.

Results showed that each 10-ng/mL increase in gestational 25(OH)D was associated with a 1.11-point higher overall cognition score (95% CI, 0.08–2.14) and a 1.21-point higher fluid cognition score (95% CI, 0.07–2.34) after full adjustment for potential confounders. No statistically significant association was observed for crystallized cognition.

Although the relationship between vitamin D status and cognition did not differ significantly by race, the associations appeared stronger in children of Black mothers. For these children, a 10-ng/mL higher 25(OH)D level was linked to a 2.99-point higher fluid cognition score (95% CI, 0.82–5.16), compared with a 0.43-point increase (95% CI, −0.93 to 1.78) in children of non-Black mothers.

The analysis also suggested that vitamin D levels earlier in pregnancy might be most important for neurodevelopment. In exposure pattern modeling, the largest divergence in 25(OH)D concentrations between children with higher and lower cognitive scores was observed in early gestation.

“Our study provides important new evidence that early pregnancy may be a critical period when vitamin D has the greatest potential to support cognitive development,” said Melissa M. Melough, PhD, RD, of the University of Delaware, Newark. “This highlights a key opportunity for clinicians to enhance screening and support for vitamin D supplementation before and during pregnancy.”

Vitamin D deficiency was common in the study population, affecting approximately 38% of participants. The prevalence was higher among Black mothers (56.9%) compared with White mothers (31.0%). Deficiency was also more common among participants with lower maternal education levels, prepregnancy obesity, and prenatal nicotine use.

The authors noted that vitamin D plays an important role in brain development through its actions on neuronal and glial cells, regulation of neurotrophic factors, and modulation of neurotransmitter synthesis. Experimental evidence from animal models suggests that deficiency during gestation can alter brain morphology and disrupt neuronal differentiation.

While previous studies have linked prenatal vitamin D status to early childhood cognitive outcomes, evidence for sustained effects into later childhood has been inconsistent. The present study extends the follow-up period to school-age years and includes a racially and socioeconomically diverse cohort, addressing limitations of earlier research.

The researchers emphasized that the findings should not be interpreted as establishing causality and that further studies, including randomized controlled trials, are needed to determine optimal vitamin D intake and timing during pregnancy for cognitive benefits. They also noted that postnatal factors, such as educational environment and family resources, may influence crystallized cognition and could explain the lack of association with that domain.

Given the high prevalence of vitamin D deficiency during pregnancy, particularly among groups at increased risk, the authors suggest that public health strategies promoting adequate vitamin D intake before and during pregnancy could have population-level benefits for child neurodevelopment. “Promoting vitamin D adequacy beginning in early pregnancy may enhance cognitive development in children,” the authors concluded.

References:

1. Melough MM, McGrath M, Palmore M, et al. Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program. Am J Clin Nutr. 2025;122(2):571-581. doi:10.1016/j.ajcnut.2025.06.017
2. Environmental influences on Child Health Outcomes. Vitamin D during pregnancy may play a role in children’s cognitive development, ECHO study suggests. eurekalert. August 6, 2025. Accessed August 12, 2025. https://www.eurekalert.org/news-releases/1093864