Vitamin D insufficiency is associated with challenge-proven food allergy in infants.
Allen KJ., Koplin JJ., Ponsonby AL., Gurrin LC., Wake M., Vuillermin P., Martin P., Matheson M., Lowe A., Robinson M., Tey D., Osborne NJ., Dang T., Tina Tan HT., Thiele L., Anderson D., Czech H., Sanjeevan J., Zurzolo G., Dwyer T., Tang ML., Hill D., Dharmage SC.
BACKGROUND: Epidemiological evidence has shown that pediatric food allergy is more prevalent in regions further from the equator, suggesting that vitamin D insufficiency may play a role in this disease. OBJECTIVE: To investigate the role of vitamin D status in infantile food allergy. METHODS: A population sample of 5276 one-year-old infants underwent skin prick testing to peanut, egg, sesame, and cow's milk or shrimp. All those with a detectable wheal and a random sample of participants with negative skin prick test results attended a hospital-based food challenge clinic. Blood samples were available for 577 infants (344 with challenge-proven food allergy, 74 sensitized but tolerant to food challenge, 159 negative on skin prick test and food challenge). Serum 25-hydroxyvitamin D levels were measured by using liquid chromatography tandem mass spectrometry. Associations between serum 25-hydroxyvitamin D and food allergy were examined by using multiple logistic regression, adjusting for potential risk and confounding factors. RESULTS: Infants of Australian-born parents, but not of parents born overseas, with vitamin D insufficiency (≤50 nmol/L) were more likely to be peanut (adjusted odds ratio [aOR], 11.51; 95% CI, 2.01-65.79; P=.006) and/or egg (aOR, 3.79; 95% CI, 1.19-12.08; P=.025) allergic than were those with adequate vitamin D levels independent of eczema status. Among those with Australian-born parents, infants with vitamin D insufficiency were more likely to have multiple food allergies (≥2) rather than a single food allergy (aOR, 10.48; 95% CI, 1.60-68.61 vs aOR, 1.82; 95% CI, 0.38-8.77, respectively). CONCLUSIONS: These results provide the first direct evidence that vitamin D sufficiency may be an important protective factor for food allergy in the first year of life.