Low vitamin D levels may not aggravate lung health of COPD patients

According to a new US study, a low vitamin D status seems not to increase the risk of developing acute exacerbations in patients suffering from chronic obstructive pulmonary disease.

In the prospective cohort study, blood vitamin D concentrations and the number of acute exacerbations of chronic obstructive pulmonary disease (COPD) were measured in 973 patients with severe COPD over a one year period (1). The study results showed that the 25(OH)D levels at the beginning of the study were not associated with the subsequent risk of developing severe or acute aggravations of COPD symptoms.

The researchers commented that patients with severe COPD run the greatest risk of exacerbations as well as vitamin D insufficiency and deficiency. The negative study results were also noted to be in contrast with earlier studies in which lower vitamin D levels were associated with higher rates of respiratory infections in adults and more frequent asthma exacerbations in children. The new findings would suggest, however, that while vitamin D may influence respiratory exacerbation risk in patients with asthma, the complex symptoms associated with COPD (e.g., bacterial colonization, airway inflammation, systemic inflammation, oxidative stress) may have a greater impact on the risk of acute exacerbations of COPD than any effects caused by 25(OH)D levels.

Previously studies have suggested that low vitamin D status may influence lung function. A recent animal study indicated that vitamin D deficiency could lead to functional and structural abnormalities during lung development. Further studies have suggested that high dose supplements of the vitamin could increase the exercise capacity and strength of respiratory muscles in people with COPD.

1. Kunisaki K. M. et al. Vitamin D levels and risk of acute exacerbations of chronic obstructive pulmonary disease: a prospective cohort study. American Journal of Respiratory and Critical Care Medicine. Online publication November 2011.