Johns Hopkins researchers find that low levels of vitamin D increase risk of lung disease

A decade long study by researchers from Johns Hopkins University, the results of which were published in the Journal of Nutrition last month, offers new hope for the prevention of an incurable disease that claims close to half a million lives annually.

The 2013 Global Burden of Disease study found that each year, over 595,000 people around the world are diagnosed with interstitial lung disease (ILD), a category of illnesses which affect the interstitium, a network of tissue which expands across both lungs. ILD is incurable, and most patients will die within five years of diagnosis.

The groundbreaking Johns Hopkins study offers new hope in the prevention of this disease, however, having determined that low vitamin D levels appear to directly increase the risk of developing the lung scarring and inflammation that characterize this group of illnesses.

Low vitamin D levels linked to increased risk

As reported by Science Daily, exposure to environmental toxins like coal and asbestos, medication side effects, previous infections or certain autoimmune diseases are the direct cause of ILD in the majority of the 200,000 American patients diagnosed annually. In some cases, however, the cause of the disease cannot be determined. The research team set out to try to discover what some of these early triggers of ILD might be, with the hope that it could be prevented or treated in its earliest stages.

One of the avenues the researchers wanted to explore was the link between low vitamin D levels and the development of ILD. (Related: Another study finds vitamin D reduces risk of cancer – by 20% or more.)

“We knew that the activated vitamin D hormone has anti-inflammatory properties and helps regulate the immune system, which goes awry in ILD,” noted Erin Michos, an associate professor of medicine at the Johns Hopkins University School of Medicine, and the study’s lead author. “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.”

The researchers obtained the information for their research from the Multi-Ethnic Study of Atherosclerosis (MESA), a 10-year study which gathered information from 6,814 participants recruited between 2000 and 2002. At the start of the study, blood samples were taken, with vitamin D levels being one of the recorded measurements.

For the purposes of the study, all those with levels below 20 nanograms per milliliter (2,051 people) were considered to be vitamin D deficient. Levels of between 20 and 30 nanograms per milliliter were labeled “intermediate,” and participants with levels in excess of 30 nanograms per milliliter were found to be at recommended levels. (Related: Vitamin D myths, facts and statistics.)

CT scans of the heart showing incidental and partial views of the lungs were obtained at the outset of the study for all participants, and a decade later, 2,668 participants underwent full CT scans examined by radiologists for the presence of scar tissue or other abnormalities.

Science Daily reveals the results:

The vitamin D-deficient participants had a larger volume, on average (about 2.7 centimeters cubed), of bright spots in the lung suggestive of damaged lung tissue, compared with those with adequate vitamin D levels. These differences were seen after adjusting for age and lifestyle risk factors of lung disease including current smoking status, pack years of smoking, physical inactivity or obesity.

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.

While the researchers stress the need for further studies to confirm their findings, it would seem that boosting vitamin D levels can go a long way towards warding off ILD and other lung conditions. Vitamin D levels can be boosted by spending at least 15 minutes a day in direct sunlight, or by increasing the consumption of fatty fish and fortified dairy products.

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Sources include:

ScienceDaily.com

NewsWise.com

WebMD.com