Polymorphisms affecting vitamin D-binding protein modify the relationship between serum vitamin D (25[OH]D3) and food allergy

J Allergy Clin Immunol. 2016 Feb;137(2):500-506.e4. doi: 10.1016/j.jaci.2015.05.051. Epub 2015 Aug 7.

Abstract

Background: There is evolving evidence that vitamin D insufficiency may contribute to food allergy, but findings vary between populations. Lower vitamin D-binding protein (DBP) levels increase the biological availability of serum vitamin D. Genetic polymorphisms explain almost 80% of the variation in binding protein levels.

Objective: We sought to investigate whether polymorphisms that lower the DBP could compensate for adverse effects of low serum vitamin D on food allergy risk.

Methods: From a population-based cohort study (n = 5276) we investigated the association between serum 25-hydroxyvitamin D3 (25[OH]D3) levels and food allergy at age 1 year (338 challenge-proven food-allergic and 269 control participants) and age 2 years (55 participants with persistent and 50 participants with resolved food allergy). 25(OH)D3 levels were measured using liquid chromatography-tandem mass spectrometry and adjusted for season of blood draw. Analyses were stratified by genotype at rs7041 as a proxy marker of DBP levels (low, the GT/TT genotype; high, the GG genotype).

Results: Low serum 25(OH)D3 level (≤50 nM/L) at age 1 years was associated with food allergy, particularly among infants with the GG genotype (odds ratio [OR], 6.0; 95% CI, 0.9-38.9) but not in those with GT/TT genotypes (OR, 0.7; 95% CI, 0.2-2.0; P interaction = .014). Maternal antenatal vitamin D supplementation was associated with less food allergy, particularly in infants with the GT/TT genotype (OR, 0.10; 95% CI, 0.03-0.41). Persistent vitamin D insufficiency increased the likelihood of persistent food allergy (OR, 12.6; 95% CI, 1.5-106.6), particularly in those with the GG genotype.

Conclusions: Polymorphisms associated with lower DBP level attenuated the association between low serum 25(OH)D3 level and food allergy, consistent with greater vitamin D bioavailability in those with a lower DBP level. This increases the biological plausibility of a role for vitamin D in the development of food allergy.

Keywords: Food hypersensitivity; food allergy; gene; polymorphism; vitamin D; vitamin D binding protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alleles
  • Calcifediol / blood*
  • Child
  • Child, Preschool
  • Cohort Studies
  • Dietary Supplements
  • Female
  • Follow-Up Studies
  • Food Hypersensitivity / blood*
  • Food Hypersensitivity / epidemiology
  • Food Hypersensitivity / genetics*
  • Genetic Association Studies*
  • Genotype
  • Humans
  • Infant
  • Male
  • Odds Ratio
  • Polymorphism, Single Nucleotide*
  • Population Surveillance
  • Risk
  • Seasons
  • Vitamin D-Binding Protein / genetics*
  • Young Adult

Substances

  • Vitamin D-Binding Protein
  • Calcifediol