Vitamin D not effective for reducing asthma exacerbations in children with asthma and low vitamin D levels (VDKA)

Reference

Forno E, Bacharier LB, Phipatanakul W, et al. Effect of vitamin D3 supplementation on severe asthma exacerbations in children with asthma and low vitamin D levels. The VDKA randomized clinical trial. JAMA 2020;324(8):752-760.

Synopsis

The value of vitamin D supplementation for reducing asthma exacerbations among children with asthma and low vitamin D levels remains uncertain. These investigators identified high-risk children who met the standard diagnostic criteria for persistent asthma, aged 6 to 16 years, with serum vitamin D levels less than 30 ng/mL but greater than or equal to 10 ng/mL (until July 2017) or greater than or equal to 14 ng/mL (after that date). Eligible patients (n = 192; mean age 9.8 years) randomly received (concealed allocation assignment) daily vitamin D3 (4000 IU) or matched placebo, plus an appropriate age-related inhaled dose schedule of fluticasone propionate. Individuals who assessed outcomes using previously validated asthma control scoring tools remained masked to treatment group assignment. Complete follow-up occurred for 93.8% of participants for 48 weeks. Using intention-to-treat analysis, vitamin D levels of 30 ng/mL or higher occurred significantly more often in children in the vitamin D3 supplementation group compared with the placebo group (94.4% vs 40.7% at 16 weeks; and 87.2% vs 30.1% at 48 weeks, respectively). However, no difference was detected in any of the primary, secondary, or exploratory outcomes: time to severe asthma exacerbation, time to viral-induced asthma exacerbation, proportion of patients who were able to reduce their inhaled corticosteroid dose, total cumulative fluticasone dose, number of severe asthma exacerbations, or number of viral-induced severe exacerbations.