Effects of 25 hydroxy vitamin D levels on the severity and asthma control in school age asthma patients.

BACKGROUND: The objective was to determine vitamin D levels in patients between the ages 6 and 18 years, followed for asthma, and the relation between vitamin D levels and asthma control and severity.

MATERIALS AND METHODS: Patients with asthma and healthy volunteers between the ages 6 and 18 years were enrolled into the study as patient and control groups, respectively. Patient demographic information and clinical findings were recorded; a respiratory function test was performed. Body mass index (BMI), 25(OH) D,calcium, phosphorus, alkaline phosphatase, total IgE and eosinophil levels were determined for all patients. Asthma severity and control conditions were established based on GINA (Global Initiative for Asthma) criteria.

RESULTS: Seventy two patients with asthma and 66 healthy children were included. Compared to the control group, decreased serum vitamin D levels were detected in patient group. Thirty eight (52.8%) patients in asthma patient group had vitamin D defficiency; in this group, asthma control was poor and asthma severity was significantly higher. No significant correlation was found between vitamin D levels and gender, obesity, respiratory functions, skin test, serum eosinophil and total IgE levels.

CONCLUSION: The frequency of vitamin D deficiency and insufficiency was higher in children with asthma, compared to the controls. Lower levels of vitamin D are associated with poor asthma control and increased asthma severity.