To conduct a literature evaluation on vitamin D and paediatric asthma during the last 18 months was the purpose of this study. A combined analysis of two clinical trials of maternal vitamin D supplementation trials found that vitamin D supplementation trials had a substantial protective impact in the primary prevention of asthma and recurrent wheeze up to the age of three years. Secondary analyses from these studies have also revealed that early maternal vitamin D status may influence the response to prenatal vitamin D supplementation, with the greatest protective benefit in infants delivered to women with baseline 25hydroxyvitamin D (25OHD) levels of at least 30 ng/ml. A 6-month postnatal vitamin D supplementation experiment in black preterm newborns found that infants who received supplementation had a 34% lower incidence of recurrent wheeze at 1 year. A meta-analysis of individual patient data from published clinical trials revealed that vitamin D treatment reduced the incidence of asthma exacerbations in those with 25OHD levels less than 10 ng/ml.

Vitamin D supplementation appears to help prevent the development of asthma and recurrent wheezing in childhood, and it may also aid in the management of asthma. The level(s) of circulating vitamin D that enhances these benefits is still unknown.