Evaluation of micronutrients in stable COPD patients.

Background and objectives: Chronic obstructive pulmonary disease (COPD) is a disease characterized by malnutrition, a catabolic process, and chronic inflammation; thus, vitamin deficiency may occur frequently. We aimed to evaluate the levels of micronutrients in stable COPD patients.

Methods and study design: There were 168 COPD patients from six pulmonology departments, with 36 healthy controls. The patients also performed pulmonary function tests and filled out the St. George's Respiratory Questionnaire (SGRQ). Serum vitamin B-12 and folate levels were measured using the chemiluminescence immunoassay (CLIA) method. Plasma 25-OH D3 levels were measured by high-performance liquid chromatography (HPLC).

Results: Our results revealed vitamin D deficiency in 68.9% (mild: 59.6%, intermediate: 25.7%, severe: 14.7%), vitamin B-12 deficiency in 21.7%, and folic acid deficiency in 50% of COPD patients. There was a significant difference between the COPD and healthy control groups regarding vitamin D deficiency (68.9% vs. 16.6%; p <0.001). Mean plasma 25-OH-D level was significantly lower in COPD patients (p <0.01). There was a positive correlation of plasma 25-OH-D level with the SGRQ impact score (r = 0.174, p = 0.028) and a negative correlation with age and number of exacerbations (respectively; r = -0.248, p = 0.002, and r = -0.160, p = 0.044).

Conclusions: Vitamin D, B-12, and folate deficiencies frequently occur in COPD patients. Low plasma levels of 25-OH-D may be associated with advanced age and a higher number of exacerbations in patients with COPD. COPD patients with low vitamin D and folate may experience a decrease in quality of life.