Insufficient vitamin D supply may worsen severity of COPD

A new US study suggests that low blood vitamin D concentrations may be linked to exacerbated emphysema, one of the main conditions of chronic obstructive pulmonary disease (COPD).

The observational study measured serum vitamin D concentrations of 498 participants: some were part of a smoker control group or a non-smoker control group, and some had moderate to severe COPD (1). The patients with COPD were further divided into groups with sever and less sever levels of emphysema. The study results showed that a high percentage of participants across all groups had low vitamin D levels. Of COPD patients, 69% were vitamin D insufficient (below 30 ng/mL) and 39% were deficient (below 20 ng/mL). Lower vitamin D levels correlated with a greater damage of the air sacs of the lungs (emphysema). In addi- tion, lower vitamin D levels correlated with worse six-minute walk distance test results and bronchodilator response. The better the patients’ vitamin D levels were, the higher were the concentrations of the “Clara cell secretory protein,” which appears to protect the respiratory tract against oxidative stress and inflam- mation.

The researchers commented that these observations do not prove a causal relationship. Further research should be able to clarify whether vitamin D can help in COPD. There have been some studies which show that vitamin D supplementation may help COPD patients with severe vitamin D deficiency (2). COPD is a disease most often caused from lifelong cigarette smoking and characterized by difficulty breathing. COPD includes two main conditions: emphysema and chronic bronchitis. In emphysema, the air sacs of the lungs are damaged. Chronic bronchitis, on the other hand, is characterized by irritated and inflamed lining of airways. People with COPD usually have both emphysema and chronic bronchitis.

1. Berg I. et al. Vitamin D, Vitamin D Binding Protein, Lung Function and Structure in COPD. Respiratory Medicine. 2013; 107(10):1578–1588.
2. Janssens W. et al. Vitamin D beyond bones in chronic obstructive pulmonary disease: time to act. Am J Respir Crit Care Med. 2009; 179:630–636.