Maternal early pregnancy vitamin D status in relation to fetal and neonatal growth: results of the multi-ethnic Amsterdam Born Children and their Development cohort

TLDR

Low vitamin D during pregnancy is linked to reduced fetal growth and altered neonatal development, yet evidence is insufficient to support nationwide supplementation policies. The study examined how early‑pregnancy maternal vitamin D status relates to birth weight, SGA prevalence, postnatal growth, and whether it explains ethnic disparities. Using the Amsterdam Born Children and their Development cohort, 3,730 multi‑ethnic women were assessed at median 13 weeks, with vitamin D classified as deficient (<30 nmol/L), insufficient (30–49.9 nmol/L), or adequate (≥50 nmol/L), and associations analyzed via multivariate regression. Deficient vitamin D was associated with 114‑g lower birth weight, a 2.4‑fold higher SGA risk, and accelerated weight and length gain in the first year, but it only modestly accounted for ethnic differences.

Abstract

Low vitamin D levels during pregnancy may account for reduced fetal growth and for altered neonatal development. The present study explored the association between maternal vitamin D status measured early in pregnancy and birth weight, prevalence of small-for-gestational-age (SGA) infants and postnatal growth (weight and length), as well as the potential role of vitamin D status in explaining ethnic disparities in these outcomes. Data were derived from a large multi-ethnic cohort in The Netherlands (Amsterdam Born Children and their Development (ABCD) cohort), and included 3730 women with live-born singleton term deliveries. Maternal serum vitamin D was measured during early pregnancy (median 13 weeks, interquartile range: 12-14), and was labelled 'deficient' ( <or= 29.9 nmol/l), 'insufficient' (30-49.9 nmol/l) or 'adequate' ( >or= 50 nmol/l). Six ethnic groups were distinguished: Dutch, Surinamese, Turkish, Moroccan, other non-Western and other Western. Associations with neonatal outcomes were analysed using multivariate regression analyses. Results showed that compared with women with adequate vitamin D levels, women with deficient vitamin D levels had infants with lower birth weights ( - 114.4 g, 95 % CI - 151.2, - 77.6) and a higher risk of SGA (OR 2.4, 95 % CI 1.9, 3.2). Neonates born to mothers with a deficient vitamin D status showed accelerated growth in weight and length during the first year of life. Although a deficient vitamin D status influenced birth weight, SGA risk and neonatal growth, it played a limited role in explaining ethnic differences. Although vitamin D supplementation might be beneficial to those at risk of a deficient vitamin D status, more research is needed before a nationwide policy on the subject can be justified.