Vitamin D deficiency: What does it mean for chronic obstructive pulmonary disease (COPD)? a compherensive review for pulmonologists

ObjectivesVitamin D deficiency and Chronic Obstructive Pulmonary Disease (COPD) are both under-recognized health problems, world-wide. Although Vitamin D has long been known for calcemic effects it also has less known noncalcemic effects. Recent data have shown that Vitamin D deficiency is highly prevalent in patients with COPD and correlates with forced expiratory volume in one second (FEV1) and FEV1 decline. The objective of this work was to review the current literature on vitamin D deficiency in relation with COPD. Data sourceA literature search, using the words vitamin D and COPD, was undertaken in Pubmed database. ResultsThe noncalcemic effects of vitamin D relating with COPD may be summarised as increasing antimicrobial peptide production, regulation of inflammatory response and airway remodelling. Vitamin D inhibits the production of several proinflammatory cytokines and leads to suppression Th1 and Th17 responses which may be involved in the pathogenesis of COPD. Vitamin D insufficiency may also contribute to chronic respiratory infections and airway colonization so returning vitamin D concentrations to an optimal range in patients with COPD might reduce bacterial load and concomitant exacerbations.Vitamin D is also important for COPD-related comorbodities such as osteoporosis, muscle weakness and cardiovascular diseases. Data about the effect of Vitamin D supplementation on those comorbidities in relation with COPD are been scarce. ConclusionImproving the blood level of Vitamin D into the desired range may have a beneficial effect bones and muscles, but more studies are needed to test to test that hypothesis.