Background: Bronchial asthma is a prevalent health problem. Asthma is characterized by chronic airway inflammation that is thought to have both genetic and environmental roots. Low vitamin D levels have been suspected for a long time as a possible cause of asthma. Lack of vitamin D has been connected to the rising incidence of asthma seen in recent decades. Objective: Assessment of vitamin D in children with bronchial asthma and its relation to severity of the disease. Methods: Vitamin D and bronchial asthma were searched for on Science Direct, Google Scholar, and PubMed. The authors also reviewed the relevant literature, however only the most recent or comprehensive study from April 2004 to August 2021 was included. There are no translation resources available, thus non-English documents are out. Unpublished articles, oral presentations, conference abstracts, and dissertations were not included because they were not considered to be part of major scientific projects. Conclusion: Whether or not vitamin D is associated with asthma and allergies is still up for debate. A higher risk of vitamin D deficiency has been associated with asthma, according to certain studies, Vitamin D supplements may increase allergy risk, according to several studies.