Association between serum 25-hydroxyvitamin D concentration and severity of seasonal allergic rhinitis in Karaganda region (Kazakhstan)

Background: Vitamin D deficiency (VDD) is the one of the major public health problem affecting approximately one billion people all over the world. In recent years, the relationship of allergic diseases with a low concentration of vitamin D has been studied worldwide. An association has been found between small count of serum vitamin D and the development of immune disorders. Patients with allergic disorders and, in particular, with respiratory allergy are susceptible for VDD. Objective: The study was aimed to assess the levels of serum 25-hydroxyvitamin D (25(OH)D) and their associations with the severity of seasonal allergic rhinitis in the Karaganda region (Kazakhstan). Material and methods: This cross-sectional study included 416 patients with seasonal allergic rhinitis aged 18-65 years (mean age 39±8 years), 267 of whom were females. VDD was defined as serum concentrations of 25(OH)D below 20 ng/ml. Results: The median concentration of 25(OH)D in blood serum was below the reference threshold (20 ng/ml) and amounted to 16.1 ng/ml. 75% of patients with seasonal allergic rhinitis had VDD and this was common in all age categories. VDD was more prevalent in female patients (82.8%) as compared with the male patients (61.1%) (p<0,01). Of interest is the fact that low serum 25(OH)D concentration correlated with the severity of symptoms (r =-0.94 and r =-0.67). Conclusion: According to our study, the significant part of patients with allergic rhinitis residing in Karaganda region (Kazakhstan) had deficient status of 25(OH)D and this correlated with the severity of symptoms.