Low vitamin D levels may increase the risk of respiratory disorders

According to a new study from UK low blood vitamin D concentrations seem to be linked to the development of respiratory disorders such as asthma, upper and lower respiratory tract infections, pneumonia and tuberculosis.

The observational study assessed serum 25-hydroxyvitamin D concentrations and documented cases of
long-term respiratory tract disorders of 2,070 adults aged 65 and older (1). The study results showed that participants who were severely vitamin D deficient (below 14 ng/ml) were twice as likely to suffer from a respiratory disease as those with higher vitamin D levels (above 25 ng/ml). Participants with moderate deficiency (14–20 ng/ml) had 1.75 times more likely to have a respiratory disease.

The researcher concluded that ensuring adequate vitamin D levels is of public health importance for older populations living in northern latitudes and may be an effective way to prevent concurrent respiratory infections and related complications in older people. Further studies are required to investigate whether vitamin D supplementation reduces the incidence and exacerbations of respiratory disease, they said. Vitamin D has a role in immunomodulation, which is important in respiratory health. Adequate vitamin D concentrations may be important, for example, in ameliorating chronic obstructive pulmonary disease (COPD), in which there is an abnormal inflammatory reaction to inhaled particles and a weak immune response, but recent studies have reached conflicting findings (2, 3).

1. Hirani V. Associations between vitamin D and self-reported respiratory disease in older people from a nationally representative population survey. Journal of the American Geriatrics Society. Published online May 2013.
2. Persson L. P. J. et al. Chronic obstructive pulmonary disease is associated with low levels of vitamin D. PLoS ONE. 2012; 7(6).
3. Kunisaki K. M. et al. Vitamin D levels and risk of acute exacerbations of chronic obstructive pulmonary disease. A prospective cohort study. Am J Respir Crit Care Med. 2012; 185:286–290.