Season of Birth Effects on Early Child Language Development: The Role of Maternal Vitamin Supplementation

I will present ongoing research on the impact of season of birth on early child language development. First, I will discuss a study involving 448 12-month-olds and 724 24-month-olds, revealing the influence of seasonality on language production in 12-month-old infants. Next, I will present results from a second study with 816 participants tested at 6, 12, and 18 months of age, demonstrating season-of-birth effects on cognitive scores. Furthermore, this study reveals interactions between season of birth, latitude, and prenatal maternal vitamin supplementation for expressive vocabulary. Importantly, maternal vitamin supplementation significantly reduces the influence of season of birth on language development. These findings suggest that maternal vitamin supplementation during pregnancy mitigates season-of-birth effects on infant language, potentially protecting against vitamin D deficiency and viral aggressions to the developing foetus CNS system during winter months.