The role of vitamin D in the development of asthma

The Role Of Vitamin D in The Development of AsthmaObjectives: Recently some studies are published concerning about the role of vitamin D in asthma as in some other diseases. In this study, we aimed to evaluate the effect of serum vitamin D level and vitamin D deficiency on the development and clinical features of asthma.Material and Method: 88 stable and 24 exacerbated asthma patients and similar aged and gender 94 healthy adults as control group is evaluated in the study. Detailed demographic data and clinical features, pulmonary function tests results of all participants are recorded. Serum 25(OH)D3 is analyzed with high pressure liquid chromotography technique. Serum vitamin D levels ?20 ng/ml is accepted as vitamin D deficiency.Results: The group of patients with asthma, 86 (76.8%) were female, mean age was 43.7 ± 14.2 years, while the healthy control group, 62 (66%) were female, mean age was 45.1 ± 10.4 years. The mean serum vitamin D level in all asthmatic patients (n = 112) group was 25.19 ± 12.01 ng/ml while the control groups? was 27.09 ± 12.9 ng/ml, respectively, and there was no significant difference between the two groups (p = 0, 27). There was no significant difference between stable asthma group, exacerbated asthma group and the control groups? mean serum vitamin D levels and vitamin D deficiency (respectively p=0.398, p=0.363). In contrast to the control group, serum vitamin D levels of all asthmatic females (23.89 ± 11.92 ng / ml) was significantly lower than males (29.52 ± 11.48 ng / ml) (p = 0.03). FEV1 (L) and FVC (L) levels were significantly lower in the vitamin D deficient group of both the asthmatic and the control group (respectively in patients p = 0.003, p = 0.01, in control group p = 0.04, p = 0.005). Also serum vitamin D level was significantly positively correlated with FEV1 (L) and FVC (L) levels in both groups (respectively in patients p = 0.004, p = 0.03, in control group p = 0.01, p = 0.04). In stable asthma group (n=88), mean serum vitamin D level of obese patients (22,8±13,3 ng/ml) was significantly lower than non-obese patients (27,9±11,2 ng/ml), the difference was significant (p=0,024). Again in the stable asthma group, body mass index and serum vitamin D levels were significantly negatively correlated (p=0,02)Conclusion: As a result of this study, the serum vitamin D levels and vitamin D deficiency were not different from control group, but significantly associated with female gender, poor lung function and obesity. In order to determine the effect of vitamin D on the development of asthma, further studies that contain both serum vitamin D level measurement and genetic analysis are needed.Key words: asthma, lung functions, vitamin D