Researchers from Queen Mary University of London and the University of Edinburgh found no evidence that vitamin D supplementation reduces asthma attacks. Cochrane Systematic Review Database.
The scientists analyzed the results of 20 high-quality studies. A total of 1,155 children and 1,070 adults with asthma took part.
The review did not show any effect of vitamin D supplementation on asthma control, even in people with vitamin D deficiency. The dose of the drug was also not significant. Most studies tested the effects of cholecalciferol, and one study tested the effects of calcidiol, another form of vitamin D. This drug slightly reduced the frequency of asthma attacks, so scientists recommend further research.
Additionally, the researchers did not look at the benefit of vitamin D supplementation in severe asthma deficiency or severe asthma.
Some studies have previously shown that vitamin D deficiency is associated with an increased risk of severe asthma attacks. Among them was a previous review of the authors. It was published in 2016, and scientists agree that much more data has emerged since then. The results of the new review may be prioritized as higher quality studies are included.
Also, the discrepancy between the two reviews can be explained by the increased use of vitamin D supplements by people in recent years, which in turn has reduced the incidence of deficiency.
The authors’ conclusions highlight the need to update reviews as new studies emerge.