Objective: To study the association between vitamin D levels and asthma severity and to correlate it with Absolute Eosinophil CountMethod: This is a cross sectional study done in SSIMS and RC, Davangere over a period of 2 years. A total of 100 proven cases of asthma were chosen as the study sample. All these cases were subjected to estimation of vitamin D levels and AEC. The study group was divided into vitamin D deficient (<20ng/ml), vitamin D insufficient (between 20ng/ml and 30ng/ml) and vitamin D sufficient (>30ng/ml) group. AEC of >350 was taken as high value. The effect of vitamin D deficiency and insufficiency on severity of asthma and AEC was estimated. Results: Out of the study population 37% had vitamin D deficiency, 22% had vitamin D insufficiency and 41% had sufficient vitamin D levels. All cases with vitamin D deficiency and 72% of individuals with vitamin D insufficiency had AEC >350 which was statistically significant. All cases of severe persistent asthma and 82% of moderate persistent asthma had vitamin D deficiency. Conclusion: Severity of asthma increases with vitamin D deficiency and low vitamin D levels are associated with raised absolute eosinophil counts.