Vitamin D not the Answer for Severe Asthma Exacerbations in Children

Erick Forno, MD

Vitamin D does not help reduce severe asthma exacerbations (SAE) in children, according to a new study.

In a study planned for presentation at the American Thoracic Society (ATS) 2020 International Conference, a team led by Erick Forno, MD, Pediatric Pulmonary Medicine, University of Pittsburgh, tested whether vitamin D can be effective in treating patients with severe asthma exacerbations.

In the past, observational studied have linked low vitamin D levels with severe asthma exacerbations. However, it is not entirely clear whether vitamin D supplementation prevents these exacerbations in children.

In the double-blind randomized placebo-controlled trial dubbed the Vitamin-D-Kids Asthma (VDKA) trial, investigators examined 192 children between 6-16 years with mild persistent asthma ≥1 SAE in the prior year, and serum vitamin D ≥14 but <30 ng/ml at 7 centers.

The participants had a mean age of 9.8 years old and an average of 2.1 severe asthma exacerbations in the prior year.

The study included a four-week run-in period where patients were given lose-dose inhaled corticosteroids and placebo medication. The participants were then randomized to vitamin D₃ 4,000 IU/day or placebo for 48 weeks.

The investigators sought a primary outcome of time to a severe asthma exacerbation, defined as use of systemic corticosteroids for ≥3 days, or a hospitalization/ED visit requiring systemic corticosteroids.

They also sought secondary outcomes of time to a viral-induced SAE, the ability to halve the ICS dose at the trial midpoint, and cumulative ICS dose.

The investigators conducted in-person visits following randomization, with phone calls in-between. They also measured vitamin D levels at baseline and then at 16-week intervals.

However, the trial was ultimately stopped early because of futility, following an interim analysis requested by the Data Safety and Monitoring Board.

At the conclusion of the trial, the proportion of patients achieving a vitamin D level ≥30 ng/ml was much higher in the vitamin D arm than in the placebo arm (87.2% vs 30.1%; P <0.0001), but there was no significant difference in the proportion of participants with ≥1 SAE between the vitamin D (37.5%) and placebo (34.4%) arms (P = 0.65).

Vitamin D supplementation did not improve the time to a SAE (adjusted HR, 1.16; 95% CI,0.71-1.88; P = 0.34), the number of SAEs (Beta, -0.15; 95%CI, -0.52-0.24; P = 0.46), or the time to a viral-induced severe asthma exacerbation (P = 0.96).

Vitamin D treatment also did not allow a reduction of the ICS dose (30.8% vs 31.9% of participants; OR, 0.95; 95%CI, 0.51-1.81, P=0.91). Vitamin D supplementation also did not lead to a reduction in the final cumulative ICS dose (59 vs 54.5 mg; P = 0.10).

“Vitamin D₃ supplementation did not prevent SAEs or allow reduced ICS dosing in children with mild persistent asthma and low vitamin D levels,” the authors wrote.

The study, “Vitamin D Supplementation and Severe Disease Exacerbations in Children with Asthma and Low Vitamin D Levels: A Randomized Controlled Trial,” was published online by the ATS International Conference.