5. Conclusions
In summary, we demonstrate that higher 25(OH)D early in childhood is associated with higher scores on neurodevelopmental testing. We also link higher dose maternal vitamin D supplementation and higher maternal 25(OH)D concentrations during pregnancy with better language development in offspring. Additionally, our results illustrate that the various VDBP genotypes may affect different domains of neurodevelopment in different ways, with children who have the Gc1f1s or Gc1f2 genotypes having higher academic scores and lower language scores. Together, these results indicate the importance of ensuring vitamin D sufficiency early in life, provide support for the use of higher doses of vitamin D supplementation during pregnancy, and confirm the need for further studies investigating the potential role of genetics in the relationship between vitamin D status and neurodevelopment.