Serum level of vitamin D and trace elements in children with recurrent wheezing: a cross-sectional study

Background: We aimed to show the relationship between recurrence of wheezing and serum levels of vitamin D, zinc, and copper in wheezy children compared with a healthy group. Methods: In this cross sectional study, seventy-three children with wheezing and seventy-five controls were included without a follow-up period. The clinical characteristics of the children were assessed, the asthma predictive index and temporal pattern of wheeze were determined. The serum levels of vitamin D, zinc, and copper were measured. Pearson correlation analysis was used to evaluate the relationship between homogeneously distributed variables. Results: Thirty-two of the seventy-three children (43.8%) had more than three wheezing attacks (recurrent wheezing). The Asthma Predictive Index index was positive in 26 patients (35.6%). When classified to temporal pattern of wheeze, fifty-three of the study group (72.6%) had episodic wheezing and the remainder (27.4%) was classified as multiple-trigger wheezing. We found no overall significant difference between the study and control group in terms of vitamin D and trace elements. The vitamin D and zinc levels were significantly lower and serum copper and copper/zinc ratio was significantly higher in patients with recurrent wheezing (p = 0.03, p < 0.01, p = 0.013, p < 0.01, respectively) positive Asthma Predictive Index and multiple-trigger temporal pattern of wheeze compared with patients with non-recurrent wheezing, negative Asthma Predictive Index and episodic temporal pattern of wheeze. Conclusion: It may be postulated that for the determination of asthma risk in patients with recurrent wheezing, the serum level of vitamin D, copper and zinc can be used as a routine biomarker alongside the Asthma Predictive Index and temporal pattern of wheeze.