Taking vitamin D supplements does not reduce the risk of asthma attacks in children or adults, according to an updated Cochrane Review.
The previous review found that vitamin D deficiency was linked to an increased risk of severe asthma attacks. Data in the new assessment are taken from 20 randomised controlled trials involving 2225 participants with asthma (compared with nine trials and 1093 subjects in the 2016 review), and include better representation of children with asthma than the previous review. Researchers compared patients assigned to take a vitamin D supplement with those given a placebo, and found no statistically significant difference in the number of people who experienced an asthma attack requiring treatment with a course of steroid tablets.
WIPH author Chris Griffiths said: Asthma continues to kill, and we need the best, most up to date evidence on what works to reduce the risk of attacks. Evidence from trials rarely stands still, and contrasting findings here ironically may be because more people are taking supplements because of widespread media coverage of previous trial results in favour of vitamin D supplementation. Our results also show us that more evidence is needed in people with severe vitamin D deficiency.
Williamson A, Martineau AR, Sheikh A, Jolliffe D, Griffiths CJ. Vitamin D for the management of asthma. Cochrane Database of Systematic Reviews TBD, Issue TBD. Art. No.: CD011511. DOI: 10.1002/14651858.CD011511.pub3.