FRIDAY, Aug. 12 (HealthDay News) -- Vitamin D deficiency (VDD) increases the risk of food sensitization (FS) in children with certain single-nucleotide polymorphisms (SNPs), specifically in IL4, according to a study published online Aug. 5 in Allergy.
Xin Liu, M.D., Ph.D., from Northwestern University in Chicago, and colleagues examined whether cord blood VDD was associated with FS, and if this association could be modified by genetic variants. A total of 649 children were enrolled at the time of their birth and followed thereafter (44 percent with VDD). VDD was defined as cord blood 25 hydroxyvitamin D (25[OH]D) levels of less than 11 ng/ml and FS as specific immunoglobulin E (IgE) of 0.35 kUA/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.
The investigators found that 37 percent 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 (odds ratio, 1.79). SNPs in MS4A2, FCER1G, and CYP24A1 revealed similar but weaker interactions. A strong gene-VDD interaction was found when all four SNPs were considered simultaneously.
"Our data demonstrate that VDD may increase the risk of FS among individuals with certain genotypes, providing evidence of gene-vitamin D interaction on FS," the authors write.