RESUMO
It has been recogni/ed that, in addition to Us classical function, vitamin D modulates a variety of processes and regulators systems including host defense, inflammation, and immunity. Some authors concluded that there is strong relation between vitamin I] serum level and lung functions but others concluded that there is no relation between them. To stuck the role of serum level of 25 hydroxy-vitamin D in COPD patients, also, assess the serum level of vitaniin D dependent LL-37 and IFNgamma and to study the link between the three parameters and pulmonary functions in these patients. This study was conducted on 40 persons who were divided into Gl. 10 controls and GIl. 30 COPD patients. FF.V1. serum levels of 25 hydroxv vitamin D. LL-37 and IFNgamma were measured. Serum levels of 25 hydroxy vitamin D and LL-37 were significantly decreased in GIl as compared to GI while serum llevel of IFNgamma was significantly increased in Gil as compared to GI and there was a significant positive correlation between vitamin D level and FEV1 and LL-37 level while there was a negative correlation between it and IFNgamma level. Vitamin I] level affects pulmonary function in COPD through its effect on LL-37 and IFNgamma serum level