Low vitamin D levels in children may increase food allergy risk

According to a new Australian study, a sufficient vitamin D supply may be an important protective factor against food allergies in the first year of life.

The observational study measured serum 25-hydroxyvitamin D concentrations of 577 one-year-old infants who had been shown in a skin prick test to be allergic, sensitized but tolerant, or non-allergic to peanut, egg, sesame seed, cow’s milk and/or shrimp (1). The study results showed that infants with vitamin D insuffi-ciency (below 50 nmol/L), whose parents were born in Australia, were more likely to be peanut and/or egg allergic than were those with adequate vitamin D levels independent of eczema status. Children with two or more allergies were 10 times more likely to have vitamin D deficiency.

The researchers commented that vitamin D could play an important role in regulating a child’s immune system in the first year of life. It is likely that reduced diversity of bacteria in the gut due to increased hygiene explained the current food allergy epidemic, with vitamin D and an infant’s diet also being crucial factors. The next step is to conduct a trial to provide infants with either vitamin D supplementation or placebo in the first year of life, to see if vitamin D could protect against food allergies or possibly help in developing tolerance to certain foods.

Australia has one of the highest rates of food allergies in the world, affecting more than 10 percent of infants. Until recently, Australia also had one of the highest rates of vitamin D deficiency, and was one of the few countries that did not fortify foods with vitamin D or provide supplements to infants.

1. Allen K. J. et al. Vitamin D insufficiency is associated with challenge-proven food allergy in infants. Journal of Allergy and Clinical Immunology. Published online March 2003.