# The KLOTHO Birth Cohort: Maternal and Neonatal Vitamin D Status and Neurodevelopmental Outcomes at 10 Years

## TL;DR

A study of 66 mother-child pairs found that vitamin D levels during pregnancy and at birth did not significantly affect children's cognitive abilities at age 10, though a possible link to psychosocial development was suggested.

## Contribution

The study provides new empirical evidence on the relationship between perinatal vitamin D status and neurodevelopmental outcomes in children.

## Key findings

- Maternal vitamin D deficiency was not associated with cognitive composite scores in children at 10 years.
- A non-significant negative trend was observed between maternal vitamin D and psychosocial composite scores.
- Exploratory analysis suggested a positive association between maternal vitamin D and psychosocial development in a small subset.

## Abstract

Background: Maternal vitamin D status during pregnancy has been hypothesized to influence offspring neurodevelopment; however, the evidence remains inconsistent. Methods: We studied 66 mother–child pairs from the KLOTHO cohort with serum 25-hydroxyvitamin D [25(OH)D] measurements at delivery (maternal and umbilical cord). At 10 years of age, neurodevelopment was assessed using standardized questionnaires, generating composite z-scores for cognitive (cognitive, communication, motor) and psychosocial (social–sentimental, special interests) domains. Multivariable models were adjusted for sex, maternal body mass index and education, and neonatal birth weight and gestational age. Results: Maternal 25(OH)D deficiency (<50 nmol/L) was not associated with cognitive composite scores (p = 0.77). The psychosocial composite scores showed a non-significant negative trend (p = 0.29). Neonatal deficiency showed no consistent association with cognition (p = 0.99) or psychosocial outcomes (p = 0.30). Exploratory partial correlations suggested a positive association between maternal 25(OH)D and psychosocial development (r = 0.60, p = 0.038, n = 12). Seasonal variation in maternal vitamin D was observed (autumn: 56.0 ± 24.6 vs. winter: 32.0 ± 18.3 nmol/L; p < 0.0001), but did not translate into differences in 10-year outcomes. Conclusions: In this cohort of 66 pairs, perinatal vitamin D status was not a determinant of global cognition at 10 years of age. A potential link with psychosocial development requires replication in larger longitudinal studies. Due to the limited sample size, all findings should be interpreted as exploratory.