Orthomolecular Therapy and Asthma in Children

Inclusion Criteria: * Male or female aged 7 to 18 years * Mild to moderate asthma diagnosed by a respirologist * Use of budesonide at a dose of 200-800 µg/d (or equivalent corticosteroid therapy) for ≥3 months * Stable asthma, defined as no significant change in the regular asthma medication and no acute asthma exacerbation requiring corticosteroid rescue for at least 3 months before enrollment in the run-in phase. Asthma symptoms must be under good control * Baseline forced expiratory volume at 1 second (FEV-1) \>= 70% of the predicted normal value. * Possible participants treated with orthomolecular therapies within the previous year will require a wash out period of 7 days prior to enrolment in the trial. (Vitamin C \> 200mg, Vitamin E \>50IU, Vitamin B12 \> 100µg, Magnesium \> 200mg, Selenium \> 50µg, Omega-3 \> 300mg, Quercetin \> 3mg, Vitamin B6 \> 75mg will all be considered orthomolecular doses). Exclusion Criteria: * Known hypersensitivity to any component of the orthomolecular therapy or placebo. * Acute infectious sinusitis or respiratory tract infection or active lung disease other than allergic asthma within 1 month or any other significant systemic disease within 3 months of the study entry visit.