A 10-year long observational study finds a link between low levels of Vitamin D and an increased incidence of inflammatory diseases of the lung including ILD
Interstitial lung disease (ILD) is not a singular disease; it is a group of disorders with inflammation and concurrent scarring as the center focus of its pathogenesis. Individuals with ILD suffer from a shortness of breath, dry cough, progressive weight loss and increased tiredness. Although the exact cause and etiology of ILD is ill-established, some important risk factors have been identified that contribute to the disease progression. These include smoking, environmental toxins such as asbestos and coal dust, autoimmune disorders, and infections, amongst others.
The statistics of ILD are sobering: the Global Burden of Disease, a tool developed by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, estimated that about 595,000 people worldwide developed ILD in 2013, while some 491,000 die each year on average from the condition. The prognosis of ILD is also pessimistic. Once diagnosed, patients of ILD live for only about five years. Currently, no cure or treatment exists for ILD.
A team of researchers at Johns Hopkins University investigated the possible risk factors of ILD by conducting a 10-year long cohort study with a study sample of over 6,000 adults aged around 63 years from different cities in the United States. The research led by Erin Michos and her team collected data on the sample population for over 10 years.
On the first clinical visit, blood samples of the participants were collected and analyzed. Thirty percent of participants were found to be Vitamin D deficient. A full CT scan of the heart with partial views of the lungs was also obtained.
After a period of 10 years, the participants underwent a full lung CT scan that showed that the population with vitamin D deficiency had a relatively larger volume of the lungs with bright spots that pointed to underlying tissue damage. Biases of the study including age, lifestyle, smoking, obesity, and comorbidities were adjusted to establish a sound association between the level of vitamin D in the blood and lung disease.
After evaluating all the data available, Michos and her team concluded that people who were vitamin D deficient showed greater signs of developing interstitial lung disease. “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," Michos explained. The research team leader added that an activated vitamin D hormone possesses anti-inflammatory properties and can serve as an immune system regulator, a function that is affected by the occurrence of ILD. Even more, “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”, concluded Michos.
ILD is a debilitating albeit a rare form of lung disorders. With a possible association between low vitamin D levels and ILD now found, there may be a way to prevent the incidence of ILD. However, further research is still needed to establish a coherent relation.
Johns Hopkins Medicine. "Low vitamin D levels associated with scarring lung disease." https://www.hopkinsmedicine.org/news/media/releases/low_vitamin_d_levels_associated_with_scarring_lung_disease?