Effect of Vitamin D Levels on Asthma Control in Adults

Abstract

The aim of this study is to evaluate the effects of serum vitamin D level on asthma control and pulmonary functions in asthmatic patients. 35 healthy controls and 60 asthma patients were included. Demographic characteristics, ACT and PFT were recorded and laboratory tests were measured. 53 asthmatic patients and 32 controls with decreased vitamin D levels were referred to the Endocrinology Department for vitamin D replacement therapy. In asthmatic patients, ACT and PFT were repeated at third month of therapy. In terms of age, sex, sociodemographic characteristics, smoking status, daily sun exposure, calcium-containing diet, and menopausal status, there was no significant difference between asthmatics and controls, and laboratory test findings were similar. Vitamin D levels were low in about 90%. While 71,7% of asthmatic patients were uncontrolled at initial admission, the rate of uncontrolled patients decreased to 13,2% after the post-replacement evaluation. There was a significant increase of ACT with vitamin D replacement. There was also significant increase in FVC, FEV1 and FEV1/FVC after replacement therapy. The mean BMI were high in both groups (≥30 kg/m²). The mean ACT score was lower in obese asthmatics than in non-obese patients, but the difference was not significant. Presence of controlled or uncontrolled disease was similar between the obese and non-obese. According to our findings, vitamin D replacement therapy has a positive effect on asthma control and pulmonary function.