A study headed by Xin Liu, M.D., Ph.D., of Northwestern University, examined whether cord blood vitamin D deficiency (VDD) was associated with food sensitization (FS) and whether the association could be modified by genetic variants. Researchers enrolled 649 children – 44% with VDD -- at the time of their birth and followed their development thereafter.
VDD was defined as cord blood 25 hydroxyvitamin D (25[OH]D) levels of less than 11ng/mL and FS as specific immunoglobulin E (IgE) of 0.35kUA/l or more to any of the eight common food allergens in early childhood. Potentially functional SNPs in 11 genes involved in regulating IgE and 25(OH)D concentration were genotyped. The effects of VDD on FS alone or in combination with SNPs were evaluated using logistic regression.
Investigators found that 37% of the children developed FS. VDD alone was not associated with FS, but when examined together with SNPs, VDD showed a significant interaction with the IL4 gene polymorphism. For children carrying the CC/CT genotypes, VDD significantly increased the risk of FS.
The study was published online in Allergy.