Asthma is a chronical disease of the airways characterized by reversible obstruction of the bronchi and airway inflammation. In recent decades, the scientific interest of the vitamin D system and its role in development of asthma and other alergic diseases has been increased. Aims of this study are to mesure and compare the serum level of 25 OHD in asthmatic and healthy children and corelate the level of 25OHD and total IgE in asthmatic children. This prospective study includes 70 children at age 2 to 14, of which 32 are children with diagnosed asthma and 38 healthy children. In both of the groups the serum level of 25 OHD was measured and by the results 18 % of the healthy children (C) and 28% of the asthma children (E) had 25OHD deficiency, 45% of C and 50% of E were insufficient and 37 % of C / 22% of E were with normal 25 OHD serum level. The mean level of 25OHD in C was 27,83 +/- 10,24 and in E 20,9 ng/ml +/- 10,72. The mean levels in both groups had statistic significant difference with p-value < 0,05. According to age no statistic significant difference was found in both of the groups. There was a statisticaly significant decreased serum level of 25 OHD in asthmatic females.In the examined group (children with asthma) there was a negative linear correlation (association) of the level of 25OHD and total IgE serum level with r=- 0,55 Vitamin D serum level measurements in asthma patients gives the possibility for discovering the connection between its deficiency and development of asthma symptoms.