Vitamin D and Food Allergy

Vitamin D and Food AllergyThis article has been reviewed by Thanai Pongdee, MD, FAAAAI

The prevalence of food allergy has increased dramatically over the past decade and has now reached epidemic levels in Western countries like Australia and the United States, with up to 10 percent of 12-month-old infants having a clinically confirmed food allergy [1]. As food allergies have increased, vitamin D levels in the population appear to have concurrently decreased. Estimates suggest that up to 50% of people in Western countries are vitamin D insufficient and up to 10% are vitamin D deficient [2, 3].

The Sunshine Vitamin
Vitamin D, sometimes called the ‘sunshine vitamin,’ is a nutrient essential for good health. It plays a major role in the maintenance of healthy bones by helping the body to absorb calcium and also has an essential role in immune system function.

Vitamin D is produced in the body through sunshine on the skin, or it can be consumed in the diet through food or supplements. Oily fish—salmon, tuna and sardines—and fish oils are the richest sources of dietary vitamin D. Other good sources are eggs (vitamin D is in the yolk), liver and vitamin D fortified foods including dairy products, margarine or infant formulas.

Vitamin D and Food Allergy – What Does the Research Say?
Areas further away from the equator (and thus with lower ambient ultraviolet radiation [UVR]) have been shown to have higher rates of childhood food allergy-related hospital admissions [4], epinephrine autoinjector prescriptions [4, 5], and peanut allergy (up to six times the risk) [6] than areas closer to the equator. Season of birth (being born in autumn or winter when there is less UVR exposure) has also been associated with higher risk of anaphylaxis [7] and food allergy [8].

A link between late introduction of egg, one of the few common dietary sources of vitamin D in the infant diet, and food allergy has been observed in a large Australian study [10]. Infants who were first given egg earlier (that is between four and six months) had significantly less food allergy than infants first given egg later (that is, after six months of age).

Research using direct measures of vitamin D from blood samples have also shown an association between low vitamin D and increased risk of allergic sensitization in children and adolescents [9] and food allergy in infants [11]. In this Australian study, infants with low vitamin D were more likely to have egg or peanut allergy and were more likely to have multiple allergies compared to infants with normal vitamin D levels.  

What Does This Mean for You?
It’s too early to say whether vitamin D can reverse food allergies. Future research is needed to answer that question. However, research is beginning to support the idea that vitamin D can protect against food allergies and vitamin D is important for overall good health.

For most people, the best way to ensure you have enough vitamin D is a combination between sensible sun exposure and adequate intake of foods containing the vitamin. Your doctor can assess your vitamin D status with a simple blood test and recommend a supplement if necessary. Supplements should only be taken under the advice of a healthcare professional, like an allergist / immunologist.  

If you’re pregnant, ensuring you have adequate vitamin D (particularly in late pregnancy) is essential to ensuring your child will have adequate levels. Infants’ vitamin D stores in the first year of life rely on the mother’s stores before birth.

References
1. Osborne NJ, Koplin JJ, Martin PE, et al. Prevalence of challenge-proven IgE-mediated food allergy using population-based sampling and predetermined challenge criteria in infants. J Allergy Clin Immunol. 2011;127(3):668–76.
2. Ginde AA, Liu MC, Camargo CA Jr. Demographic differences and trends of vitamin D insufficiency in the US population, 1988–2004. Arch Intern Med. 2009;169:626–32.
3. Mansbach JM, Ginde AA, Camargo CA Jr. Serum 25-hydroxyvitamin D levels among US children aged 1 to 11 years: do children need more vitamin D? Pediatrics. 2009;124:1404–10.
4. Mullins RJ, Clark S, Camargo CA Jr. Regional variation in EpiPen prescriptions in Australia: more evidence for the vitamin D-anaphylaxis hypothesis. Annals Allergy Asthma Immunol. 2009;103:488–95.
5. Camargo CA Jr, Clark S, Kaplan MS, et al. Regional differences in EpiPen prescriptions in the United States: the potential role of vitamin D. J Allergy Clin Immunol. 2007;120:131–6.
6. Osborne NJ, Ukoumunne OC, Wake M, Allen KJ. (2012). Prevalence of eczema and food allergy is associated with latitude in Australia. J Allergy Clin Immunol. 2012;129(3): 865–867.
7. Vassallo MF, Banerji A, Rudders SA et al. Season of birth and food-induced anaphylaxis in Boston. Allergy. 2010;65(11):1492–3.
8. Mullins RJ, Clark S, Katelaris C, Smith V, Solley G, Camargo CA. Season of birth and childhood food allergy in Australia. Pediatr Allergy Immunol. 2011;22(6):583–9.
9. Sharief S, Jariwala S, Kumar J et al. Vitamin D levels and food and environmental allergies in the United States: results from the National Health and Nutrition Examination Survey 2005-2006. J Allergy Clin Immunol. 2011 May;127(5):1195-202.
10. Koplin JJ, Osborne NJ, Wake M et al. Can early introduction of egg prevent egg allergy in infants? A population-based study. J Allergy Clin Immunol. 2010;126(4):807-13.
11. Allen KJ, Koplin JJ, Ponsonby AL et al. Vitamin D insufficiency is associated with challenge-proven food allergy in infants. J Allergy Clin Immunol. 2013;131(4):1109–16.

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