Background: Cross-sectional studies have reported association of vitamin D deficiency with increased asthma prevalence and severity, and with allergy. The effect of vitamin D as a sole therapy on airway hyperreactivity (AHR) and airway inflammation has not yet been reported.
Aim: To evaluate the effect of vitamin D therapy on AHR as assessed by methacholine challenge test (MCT), Fractional Exhaled Nitric Oxide (FeNO), systemic markers of allergy and inflammation and exhaled breath condensate (EBC) cytokines.
Patients: Children aged 6–18 years with a clinical diagnosis of mild to moderate asthma not receiving anti-inflammatory therapy and with low vitamin D levels.
Methods: Randomized, double-blind, placebo-controlled study assessing the effect of 6 weeks treatment with either oral vitamin D 14000 units once weekly or placebo on these parameters.
Results: 39 patients were included, 20 patients received vitamin D treatment and 19 received placebo. Vitamin D replacement resulted in significant increase of vitamin level while it remained unchanged in the placebo. There was no change in IgE, eosinophil count, High sensitivity C-reactive protein, FeNO levels or MCT following treatment. Similar changes in (EBC) cytokines (IL4, IL5, IL10, IL17 and γ interferon) were observed in both groups.
Conclusions: In our small group of children with mild to moderate asthma, treatment with vitamin D as a sole treatment had a similar effect as placebo in spite of significant increase in vitamin D blood levels. Further larger studies are needed to evaluate the possible therapeutic effect of vitamin D in asthma.
