Vitamin D Deficiency & Asthma

Since the early 1960s, the number of asthma cases have exploded, according to a November 2007 study published in the "Journal of Allergy and Clinical Immunology." During the same period, cases of vitamin D deficiency also skyrocketed. Could the two be linked? These dual epidemics have led Augusto D. Litonjua, MD of Brigham and Women's Hospital to ask, "Is vitamin D deficiency to blame for the asthma epidemic?"

Vitamin D Deficiency

"Vitamin D deficiency is now recognized as an epidemic in the United States," claims Michael Holick, MD of Boston University. Research published in the November 2005 "Journal of Nutrition" concluded that vitamin D deficiency was extremely common, although it was unable to make specific population-wide estimates.

Vitamin D deficiency can have serious implications for the immune system, including immune cells in the lungs.

Asthma

Asthma occurs when the lungs become inflamed and are unable to function normally. Asthma often leads to shortness of breath, coughing and lower physical activity levels. According to the National Heart Blood and Lung Institute, asthma strikes an estimated 22 million Americans, with more than 25 percent of cases occurring in children.

Prevention

In the womb, the growing fetus's lung development is highly reliant on vitamin D. This is why researchers have found a correlation between low vitamin D levels during pregnancy and asthma rates. The aforementioned "Journal of Allergy and Clinical Immunology" study found that a high vitamin D intake by the mother can drop asthma risk for the child by 40 percent.

Treatment

Vitamin D may be able to help people already afflicted with asthma. According to research out of the January 2009 edition of "The American Journal of Respiratory and Critical Care Medicine," vitamin D may ease symptoms in kids with asthma.

The study found an inverse link between vitamin D and asthma severity --- the lower the vitamin D levels, the worse the asthma attacks became. The authors concluded that "lower vitamin D levels are associated with increased markers of allergy and asthma severity."

Sources

The Vitamin D Council recommends that all healthy adults get 5,000 international units (IU) of vitamin D per day.

The best source of vitamin D is UV ray exposure from the sun. To minimize your risk of skin cancer, limit your time in the sun to 20 minutes.

Vitamin D is scarce in the food supply, but the best food sources of vitamin D are fatty fish, mushrooms, fortified cereal, soy milk and tofu.You may also want to consider a vitamin D supplement if you spend much of your time indoors.