This study in Allergy. 2013 Nov 4. doi: 10.1111/all.12278 looks at children with asthma that are treated with medication alone, subcutaneous immune therapy (SCIT), and subcutaneous immune therapy (SCIT) and vitamins D.
The results were most favorable for the vitamin D and SCIT group after 6 months of time. It appears that vitamin D took about 6 months to show its benefits and differentiate itself from the SCIT group alone.
The Vitamin D group and SCIT showed nearly 2 times the discontinuation of corticosteroid inhalers than the SCIT group alone. The medication group alone showed 0/18 able to discontinue, the SCIT along showed 3/15 and the SCIT and vitamin D showed 6/18.
Vitamin D would appear to have an important role in helping patients with asthma.
Read More at: http://www.ncbi.nlm.nih.gov/pubmed/24180595