This study was a prospective cross-sectional survey that included a total of 70 infants being followed in the Pediatric Immunology and Allergy Unit at Ondokuz Mayis University. Forty of these infants (patient group), ranging in age from 1 to 3 years, had been diagnosed as wheezy infants; 30 were age-and-gender matched healthy infants (control group). Prior to the study, blood samples were taken from both groups to determine their serum VitD, blood eosinophil, and serum immunoglobulin E (IgE) levels.