Maternal and newborn vitamin D status and its impact on food allergy development in the German LINA cohort study

Abstract Background Vitamin D levels are known to be associated with atopic disease development; however, existing data are controversial. The aim of this study was to investigate whether corresponding maternal and cord blood vitamin D levels are associated with atopic outcomes in early infancy. Methods Within the LINA cohort study (Lifestyle and environmental factors and their Influence on Newborns Allergy risk), 25( OH ) D was measured in blood samples of 378 mother–child pairs during pregnancy and at birth. Information about children's atopic manifestations during the first 2 years of life was obtained from questionnaires filled out by the parents during pregnancy and annually thereafter. Cord blood regulatory T cells (Treg) were detected by methylation‐specific PCR using a Treg‐specific demethylated region in the FOXP 3 gene. Results The median maternal 25( OH )D 3 level was 22.19 ng/ml ( IQR 14.40–31.19 ng/ml); the median cord blood 25( OH ) D 3 10.95 ng/ml (6.99–17.39 ng/ml). A high correlation was seen between maternal and cord blood 25( OH ) D 3 levels, both showing a seasonal distribution. Maternal and cord blood 25( OH ) D 3 was positively associated with children's risk for food allergy within the first 2 years. Further, higher maternal 25( OH ) D 3 resulted in a higher risk for sensitization against food allergens at the age of two. Cord blood 25( OH ) D 3 levels were negatively correlated with regulatory T cell numbers. Conclusion Our study demonstrates that high vitamin D levels in pregnancy and at birth may contribute to a higher risk for food allergy and therefore argues against vitamin D supplement to protect against allergy.