Vitamin of the Decade – Vitamin D.

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Vitamin D deficiency has recently been linked with an increased risk of cancer, heart disease and rheumatoid arthritis. We are also seeing a connection between Vitamin D deficiency and poorly-controlled asthma. An increase in cases of Vitamin D deficiency over the past several decades is thought to be one of the reasons that the prevalence of allergies and asthma has been increasing. What is different now than 50 years ago? We spend much less time outdoors, decreasing the Vitamin D made in our skin. We eat more processed foods, getting less Vitamin D through our diets. In addition, more asthma and allergies are being seen especially in industrialized countries far from the equator where there is less opportunity for sun exposure.

There are at least two reasons why a lack of Vitamin D would make asthma worse. In Vitamin D-deficient asthmatics,steroids do not work as well. Thus, the medications Advair,Symbiotic and Flovent provide less benefit. Second, Vitamin D helps the body fight off viral infections, one of the main causes of asthma attacks.

Vitamin D deficiency is not only associated with asthma but with severe, difficult-to-treat asthma. Mothers who are Vitamin D-deficient during their pregnancies are more likely to have children with allergies or asthma. Prenatal Vitamin D deficiency may affect the development of the lungs and the immune system.

What we have not proven is that supplementing low Vitamin D levels improves the control of asthma. Those studies are just now being performed. In addition, Vitamin D can be harmful if you get too much, so replacing it without a doctor tracking your blood levels may present its own challenges. We have long wondered why certain patients with severe asthma do not benefit from inhaled steroids. Hopefully, we are on our way to pro-viding some relief to those who suffer the most from asthma.

David B. Engler, MD

Note: Information contained in this article should not be considered a substitute for consultation with a board-certified allergist to address individual medical needs.