According to a new study analysis, lower than normal levels of vitamin D in the blood were linked to increased risk of early interstitial lung disease.
Reviewing medical information gathered on more than 6,000 adults over a 10-year period, Johns Hopkins researchers have found that lower than normal blood levels of vitamin D were linked to increased risk of early signs of interstitial lung disease (ILD). Interstitial lung disease is a group of disorders characterized by lung scarring and inflammation that may lead to progressive, disabling and irreversible lung damage.
An estimated 200,000 cases a year are diagnosed in the United States, caused by environmental toxins such as asbestos or coal dust, and by autoimmune disorders, infections, medication side effects and other unknown causes.
Results of the most recent data analysis, published in the Journal of Nutrition, suggest that low vitamin D levels might be one factor involved in developing interstitial lung disease. Researchers caution their results can’t prove a cause and effect, but their data does support the need for future studies to investigate whether treatment of vitamin D deficiency, such as with supplements or sunlight exposure, could potentially prevent or slow the progression of the disorder in those at risk. Currently, there is no proven treatment or cure once interstitial lung disease is diagnosed.
“We knew that the activated vitamin D hormone has anti-inflammatory properties and helps regulate the immune system, which goes awry in ILD,” says Erin Michos, MD, MHS, associate professor of medicine at the Johns Hopkins University School of Medicine and associate director of preventive cardiology at the Johns Hopkins Ciccarone Centre for the Prevention of Cardiovascular Disease. “There was also evidence in the literature that vitamin D plays a role in obstructive lung diseases such as asthma and COPD, and we now found that the association exists with this scarring form of lung disease too.”
When looking at the data from the full lung scans, the researchers said those with deficient or intermediate vitamin D levels were also 50 to 60 percent more likely to have abnormalities on their full lung scans suggestive of early signs of interstitial lung disease, compared with those with optimal vitamin D levels. These associations were still seen after adjusting for other cardiovascular and inflammatory risk factors, such as high blood pressure, high cholesterol, diabetes and levels of high-sensitivity C-reactive protein (another inflammatory marker).
“Our study suggests that adequate levels of vitamin D may be important for lung health. We might now consider adding vitamin D deficiency to the list of factors involved in disease processes, along with the known ILD risk factors such as environmental toxins and smoking,” says Michos. “However, more research is needed to determine whether optimizing blood vitamin D levels can prevent or slow progression of this lung disease.”
People can boost their vitamin D levels by spending 15 minutes a day in summer sunlight without sunscreen or through a diet that includes fatty fish and fortified dairy products. Supplements should also be considered for people with deficiency or those wishing to avoid direct sunlight.