Trends of vitamin D in asthma in the pediatric population for two decades: a systematic review.

Vitamin D has anti-inflammatory properties by multiple mechanisms. Vitamin D deficiency has been associated with increased inflammation, exacerbations, and overall worse outcomes in pediatric asthma and is seen in asthmatic children with obesity. Also, given the increase in the prevalence of asthma over the last few decades, there has been enormous interest in vitamin D supplementation as a potential therapeutic option. However, recently there have been opposite results studies suggest no strong association between vitamin D levels or vitamin D supplements and childhood asthma. Additionally, recently there have been exciting reports that obesity and vitamin D deficiency has been associated with increased asthma symptoms. Thus, this review will summarize the findings from clinical trials regarding the role of vitamin D in pediatric asthma and analyze the study trend of vitamin D for two decades.