Vitamin d levels in adult asthma and affect on asthma control

OBJECTIVE: The aim of this study was to investigate the relationship between vitamin D and adult asthma in our patient group, the relationship between serum vitamin D levels and severity of asthma and the effect of vitamin D deficiency on asthma control. MATERIAL AND METHOD: We retrospectively evaluated the relationship between level of vitamin D and control status in patients with asthma who were followed up regularly in Ege University Faculty of Medicine Chest Diseases Policlinic in asthma clinic and the deficiencies were tried to be completed prospectively. The data of adult cases who were applied for thoracic diseases in the clinic and were not detected significant respiratory pathology were taken as a control group. In the asthma group, non-asthmatic disease, using drug to affect the vitamin D level, absence of illness and BMI≥35 was considered. 25(OH)D values for vitamin D were used. Serum 25-30 (OH) D level> 30 ng/mL is accepted adequately vitamin D level, between 20-30 ng/mL is accepted Vitamin D inadequency, <20 ng/mL is D vitamin deficiency and <10 ng/mL is severe D vitamin deficiency. RESULTS: Total of 329 patients' level of vitamin D were screened from patients who applied to the Ege University Faculty of Medicine Chest Diseases Polyclinics between May 2014 and May 2016. A total of 102 asthmatic patients whose of 25 are episodes and 77 patients are stable periods and 62 healthy adults with similar characteristics as the control group were evaluated. There was no significant difference between vitamin D levels of asthmatic group and control group (p=0.047). When the level of vitamin D were compared between asthmatic patients with asthma (43.93±24.06 ng/ml) and asthmatic patients with exacerbation (29.96±18.96 ng/ml), it was observed that the level of vitamin D of the exacerbated patients were lower (p=0.07). When the group with vitamin D deficiency was compared with the group without vitamin D deficiency in asthmatic patients, it was observed that the group with vitamin D deficiency was higher in BMI (30.54±4.91 kg/m2, 28.31±5.38 kg/m2);(p=0.035). There was a linear relationship between level of vitamin D and FEV1 level, which was found to be independent of BMI and other modifying factors (p<0.001). According to the asthma control questionnaire, level of vitamin D was found to be lower in patients not under control (47.76±24.11, 30.55±19.03, p<0.001). CONCLUSION: There was no significant difference in level of vitamin D between our asthmatic patient group and healthy group, and the difference between stable asthmatic patients and asthmatic patients was found to be significant in this study. It was also observed that both pulmonary function test values of patients and level of vitamin D were low. One of the reasons for controlling patients in uncontrolled asthmatics is the need to consider level of vitamin D, which is supported by the view that asthmatic patients with low level of vitamin D are more difficult to control.