The role of vitamin D in COPD

Objectives: Since recent studies revealed conflicted results about chronic obstructive pulmonary disease (COPD) and vitamin D, in this study we aimed to determine the relationship of serum vitamin D levels and vitamin D deficiency with the development of COPD and lung functions in COPD patients.Material and Method: In this study, serum vitamin D levels were analyzed on patients who admitted to the Chest Diseases out-patient clinic in Cukurova Unıversity Balcalı Medical Faculty Hospital between July 2011 and September 2011, clinically suspected diagnosis of COPD and were diagnosed COPD by lung function tests according to GOLD criteria, over 40 years who still smoke or stopped smoking 86 stable patients and 72 healthy adults with similar age and sex. After obtaining informed consent from all patients, the demographic data, symptoms and medical history were recorded with a survey, and physical examination was performed and recorded in all patients. Venous blood sample was analyzed for serum 25(OH)D3 and also serum albumin, parathormone, calcitonin, phosphorus and calcium levels.Results: Mean serum vitamin D levels of COPD patient (24.2±9.9 ng/mL) was lower than the healthy control group (30.8±8.3 ng/mL) (p< 0,001). Vitamin D deficiency prevalence is more frequent in COPD patients (34.9 %) than control group (5,6 %). In the lineer regression analyses, (after adjustment for age, gender, body mass index and pack-years of cigarette smoking) to determine the independent factors influencing the serum vitamin D levels, FEV1 level was found the independent predictive factor of the serum vitamin D level (beta=0,286 p=0,007).In the logistic regression analyses (after adjustment for age, gender, body mass index and pack-years of cigarette smoking) when the mild and moderate COPD patients are used as reference, the risk of vitamin D deficiency is 2.8 times increased in severe and very severe COPD patients (OR:2,8, p=0,024). In addition, (after adjustment for age, gender, body mass index and pack-years of cigarette smoking) when the group A COPD patients are used as reference, the risk of vitamin D deficiency is 4.83 times increased in group D COPD patients (OR:4,83, p=0,003).Conclusion: In this study, it is found that COPD patients have decreased serum vitamin D levels and increased risk of vitamin D deficiency compared to healty control group and higher GOLD stage is associated with increased risk for vitamin D deficiency. In addition, it is shown that vitamin D is protective against the damage caused by smoking on lung function. However new long-followed, randomized-controlled studies are needed to use of vitamin D deficiency treatment in primary and secondary prevention of COPD.Keywords: Chronic obstructive pulmonary disease (COPD), pulmonary functions, vitamin D deficiency,