Association of Pulmonary Function Tests and Serum Vitamin D Levels in Asthmatics With Vitamin D Deficiency

Objective: The effects of serum vitamin D levels on the evolution or severity of asthma have been widely researched; however, conflicting results have been achieved. This study was designed to evaluate the relationship between serum vitamin D levels and pulmonary function tests in asthmatic and non-asthmatic people with vitamin D deficiency. Materials and Methods: This was a prospective cross-sectional study on healthy adults and asthmatic patients. Standard spirometry and serum 25-hydroxyvitamin D test were performed for all participants. Results: Forty asthmatic patients and 40 healthy controls were tested. The mean age of participants was 42.86 +/- 1.6. High prevalence of vitamin D deficiency was found in both the asthmatic and control groups. No significant correlation was found between serum vitamin D levels and spirometry parameters in either of the groups (P = 0.83). Conclusion: Serum levels of 25-hydroxyvitamin D were not correlated with the severity of asthma as evaluated by pulmonary function tests in asthmatics.