Vitamin D for Allergies

Vitamin D may be obtained from a well-balanced diet, including some enriched or fortified foods. In addition, the body manufactures vitamin D when exposed to sunshine, and it is recommended people get 10 to 15 minutes of sunshine 3 times a week.. © ADAM

Vitamin D is an important nutrient and hormone that is found naturally in only a few foods (oily fish, cod liver oil, egg yolks), but it is also made in the skin with sunlight exposure. It appears that vitamin D serves multiple important functions for the immune system, such as treating infections, preventing certain forms of cancer and autoimmune diseases, and regulating the development of allergies and asthma.

Allergic diseases of nearly all types have become much more common over the past few decades, possibly due in part to insufficient levels of vitamin D in the body. There are many reasons for vitamin D insufficiency, including modern lifestyles that include more time spent indoors with less sunlight exposure, and the widespread use of sunscreen. While this may be a good thing to prevent certain forms of skin cancer, the unintended consequence may be vitamin D insufficiency.

The amount of sunlight exposure it takes for the body to make an adequate amount of vitamin D depends on how much skin is exposed and a person’s skin type. The Fitzpatrick Classification Scale defines 6 skin types by complexion and tolerance of sunlight. The lower the skin type number, the less sun exposure time it takes to make vitamin D.

For example, year-round at noontime in Miami, Florida, it takes a person with a Fitzpatrick Skin Type 3 approximately 5 minutes to make an adequate amount of vitamin D if 25% of their skin is getting direct sunlight (face, neck, arms and hands are uncovered).

A person with Fitzpatrick Skin Type 5 would require 2 to 3 times more sun exposure to make the same amount of vitamin D in the same setting.

People living in year-round warm climates or during the summertime in more seasonal climates would be able to get enough sun exposure to make an adequate amount of vitamin D.

However, after 2 p.m. during the winter months in Boston, Massachusetts, it is impossible for even a person with Fitzpatrick Skin Type 1 to get enough sun exposure to make an adequate amount of vitamin D. Therefore, people living in colder climates, especially during the winter months, likely need oral supplementation in order to have an adequate amount of vitamin D in their bodies.

Before planning on increasing your sun exposure or taking a vitamin D supplement, check with your doctor. Adequate vitamin D levels can easily be obtained through supplementation, taking the need for dangerous UV exposure out of the equation, but you should discuss what is best for your specific situation.

Learn more about the association between vitamin D deficiency and allergies/asthma.


Terushkin V et al. Estimated equivalency of vitamin D production from natural sun exposure versus oral vitamin D supplementation across seasons at two US latitudes. J Am Acad Dermatol 2010 Jun; 62:929.e1

Tsiaras WG and Weinstock MA. Ultraviolet irradiation and oral ingestion as sources of optimal vitamin D. J Am Acad Dermatol 2010 Jun; 62:935.

Taback SP, Simons ER. Anaphyalxis and Vitamin D: A role for the sunshine hormone? J Allergy Clin Immunol. 2007;120:128-130.

Litonjua AA, Weiss ST. Is Vitamin D Deficiency to Blame for the Asthma Epidemic? J Allergy Clin Immunol. 2007; 120:1031-5.

Poon AH, Laprise C, Lemire M, et al. Association of Vitamin D Receptor Genetic Variants with Susceptibility to Asthma and Atopy. Am J Resp Crit Care Med. 2004; 170:967-73.

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