Vitamin D and Lung Health
This was written in the United States in 2009 but the information it contains has only seemed to reach the UK over the past 2 years or so.
Research presented on Wednesday at the American Thoracic Society’s 105th International Conference revealed a novel mechanism by which Vitamin D may help to slow or even halt the progression of asthma and COPD (Chronic Obstructive Pulmonary Disease). Scientists from the University of Pennsylvania described the ability of calcitriol (a form of Vitamin D) to reduce the growth of “airway smooth muscle” that is a hallmark of the progressive decline found in those with COPD and asthma. This type of “airway remodeling” brings about decreased lung function over time. (1)
In the current laboratory experiment, calcitriol and a powerful corticosteroid were both tested on lung cells provided by 12 asthmatic and healthy volunteers. Both substances are known to possess anti-inflammatory properties.
The researchers were surprised to find that the corticosteroid, commonly used to treat asthma, didn’t have much of an impact on the undesirable proliferation of the lung cells. On the other hand, Vitamin D showed a “dose-dependent” effect on the expansion of “airway smooth muscle”. These findings were so impressive that a human study in patients with severe asthma is already underway. It is expected to be completed in about a year.
There is also hope that Vitamin D therapy may be useful in the management of COPD, based on its ability to reduce inflammatory substances (cytokines) that play a major role in the pathology of this disease.
In the past few years, several studies have taken a look at the patterns of asthma diagnoses in various populations. An April 2009 study noted that Vitamin D is vital to proper lung development and that children with adequate levels of sun exposure and Vitamin D are less likely to suffer from wheezing illness. A scientific paper from 2007 turned its attention to the prevalence of asthma in modern times. A drastic increase in the number of asthmatics has been reported beginning in the 1960′s. Scientists theorize that this is likely due to more time spent indoors, perhaps because of growing concern about the risk of skin cancer.
There are two other areas relating to pulmonary health that may be responsive to optimal levels of vitamin D. Here’s a brief review of both of them:
- Upper Respiratory Tract Infections: A February 2009 article in the Archives of Internal Medicine looked at the Vitamin D status of 883 varied individuals (12 years and older) over the course of 6 years. A clear pattern was found that indicates that people with the lowest amount of D contracted the greatest number of upper respiratory tract infections (URTIs). As the levels of Vitamin D increased, the occurrence of URTIs decreased. The authors noted that the association between D and URTIs was greater in those with preexisting lung conditions such as asthma and COPD. (6) However, it is important to note that a recent shorter term study using Vitamin D supplements did not significantly prevent URTIs. According to researchers, longer term studies are needed to help clarify the optimal dosage and most practical application of D. (7)
- Lung Cancer: Two epidemiological studies from 2008 found a pattern of infrequent UVB (sunlight ray) exposure and low levels of Vitamin D in the blood with a greater occurrence of lung cancer. One of the studies, based on analysis derived from 111 countries, verified this increased risk in both men and women. (8) A separate study that looked at Vitamin Dblood levels only found a protective effect in women and younger individuals. (9) Once again, we’ll need more evidence to come to a firm conclusion about the role of Vitamin D in preventing lung cancer. Still, many researchers are quite optimistic about its potential. (10)
The sobering data on declining lung health should be enough to make us to take notice. In order to live an unrestricted and active life, we need a properly functioning pulmonary system. Every cell in the body absolutely requires the oxygen that our lungs provide. We may not be able to do a lot about the pollution in the air, but we can use the clues that science provides in order to protect every part of the body the best way we know how.
May 26, 2009 Written by JP Healthy Fellow Your National Health Critic