Lack of Sun Might Hurt Your Lungs

Researchers have found a relationship between vitamin D deficiency and a specific type of interstitial lung disease.

Researchers from the University of Cincinnati College of medicine analyzed levels of vitamin D in 118 patients with interstitial lung disease, 67 of which had a specific form of the disease associated with connective tissue disease. Their results distinguish between vitamin D "deficiency" and "insufficiency."

Interstitial lung disease is a group of disorders mainly characterized by scarring of lung tissue.

Vitamin D deficiency is defined as lower than normal levels of vitamin D associated with a variety of symptoms such as osteoporosis, heart disease, and hypertension among others. Someone with a vitamin D insufficiency also has lower than normal levels of vitamin D but lacks the signs and symptoms of deficiency.

After evaluating patients' vitamin D levels, researchers found that 38 percent of the study's participants had vitamin D deficiency, while an even greater number (59 percent) had vitamin D insufficiency. Those with connective tissue disease were much more likely than those with other kinds of interstitial lung disease to have vitamin D deficiency and insufficiency.

More specifically, 52 percent of connective tissue disease patients had vitamin D deficiency compared to 20 percent of patients with other types interstitial lung disease. Researchers found an even greater discrepancy in rates of vitamin D insufficiency (79 percent versus 31 percent).

According to the study's authors, the greater prevalence of vitamin D deficiency and insufficiency in patients with connective tissue disease suggests that vitamin D may play a role in the development of this specific type of interstitial lung disease.

This study appears in the February issue of the journal Chest.