Vitamin D Supplementation Can Reduce Severe Asthma Attacks in Adults

Oral vitamin D supplementation, in addition to asthma medications, could reduce the risk of asthma attacks requiring hospital attendance by 50%, according to the results of a recently published study in The Lancet Respiratory Medicine.

Funded by the National Institute for Health Research, the meta-analysis examined individual data from 955 participants from 7 trials that examined the effect of vitamin D supplementation on asthma exacerbations. The researchers found that taking oral vitamin D supplements accounted for a 30% reduction in the rate of asthma attacks requiring treatment with steroids, from 0.43 events per person per year to 0.30. Additionally, the risk of experiencing at least 1 asthma attack requiring emergency department attendance and/or hospitalization was reduced by 50%.

Participants with low vitamin D levels at the start of the trial experienced a more statistically significant protective effect from vitamin D supplementation, with a 55% reduction in the rate of asthma attacks requiring steroid treatment. However, the researchers did note that the relatively small numbers of patients within subgroups was a limitation and that they did not find definitive evidence to demonstrate that vitamin D supplementation effects differ according to baseline vitamin D status.

The researchers did not see any instances of excessively high calcium levels or renal stones, and rates of serious adverse effects did not differ between those taking vitamin D and those on a placebo. They indicated that although vitamin D supplementation demonstrated protective benefits in the study participants, the findings cannot be generalized across patient groups.