Asthma is the most common chronic disease in childhood, with a prevalence of 10 to 30%. The onset of the disease is at the age of 5 and at this time the prevalence is higher in boys than girls (ratio 3:2.5), but during adolescence, the incidence is equal in both sexes. The present study is a systematic review study conducted by searching the databases of Elsevier, PubMed, Springer, and Wiley and with the keywords of Asthma, Children, Childhood, Vitamin D, and airway inflammation and the studies between 2009 and 2020 were reviewed. Out of a total of 627 articles, 17 articles were finally selected based on the inclusion and exclusion criteria for further review; The results of the reviewed studies indicate an association between serum vitamin D levels and the incidence of asthma and asthma attacks, as well as control of the disease, lung function, and consumed dosage of corticosteroids. Although some articles have found no association, in general, vitamin D is effective in reducing inflammation in various parts of the body and strengthening the immune system function, and this affects the lung structures. However, further studies are needed to better understand the role of vitamin D in children with asthma and to explore the relationship between vitamin D and other factors involved in the development and exacerbation of the disease.

Keywords: Vitamin D, childhood, Children with asthma, Vitamin deficiency