Researchers in New York examined serum vitamin D levels in the blood of more than 3,100 children and adolescents and 3,400 adults.
No association was found between low vitamin D levels and allergies in adults, but the link was significant in children and adolescents.
Children and adolescents aged 1 to 21 with low vitamin D levels were at increased risk of having sensitivities to 11 of 17 allergens tested, including environmental and food allergies.
For example, children who had vitamin D deficiency, which was defined as less than 15 nanograms of vitamin D per milliliter of blood, were 2.4 times more likely to have a peanut allergy than kids with sufficient levels, or 30 nanograms of vitamin D per milliliter of blood.
Children with low vitamin D levels also had increased risk of allergic sensitization to shrimp, dogs, cockroaches, ragweed, oak, ryegrass, Bermuda grass, and thistle.
Avoiding Vitamin D Deficiency
The data came from the National Health and Nutrition Examination Survey 2005-2006 (NHANES), which is a program of studies aimed at assessing the health and nutritional status of adults and children in the U.S.
The study participants underwent blood tests measuring levels of Immunoglobulin E(IgE), a protein that is produced when the immune system responds to allergens.
Researchers say their findings don’t prove that insufficient vitamin D causes allergies in children and adolescents, but strongly suggests that young people should get adequate amounts of the vitamin.
“The latest dietary recommendations calling for children to take in 600 IU of vitamin D daily should keep them from becoming vitamin D deficient,” researcher Michal Melamed, MD, MHS, of the Albert Einstein College Medicine of Yeshiva University, says in a news release.
The study says vitamin D is thought to have anti-inflammatory effects in the body.
The researchers note that the prevalence of vitamin D deficiency is increasing in the U.S., and so is the prevalence of food allergies.
The study is published in the Feb. 17 online edition of the Journal of Allergy and Clinical Immunology.