Does vitamin D supplementation improve asthma control?

Giving vitamin D supplements as an adjunct to standard treatment does not lead to better asthma control in children, according to a recent randomized, controlled trial in India. ­The 3-month trial was conducted in 60 youngsters aged 6 to 11 years who had moderate persistent asthma. Half of the participants were assigned to the intervention group and received 2000 IU of vitamin D per day. The other 30 children, assigned to the control group, received a daily placebo. At baseline, all participants underwent spirometry and fractional exhaled nitric oxide (FeNO) testing and were evaluated for the best forced expiratory volume in 1 second (FEV₁). Blood samples were taken to evaluate serum 25(OH)D levels. All participants were treated with daily doses of budesonide 400 μg and formoterol 24 μg. Patients also used a diary to record symptoms, such as cough, breathlessness, sleep disturbance, school absences due to asthma, and use of rescue medicine. Participants were evaluated at monthly clinic visits, with asthma control assessed by the Childhood Asthma Control Test (C-ACT).

As expected, at the trial’s conclusion 12 weeks later, vitamin D levels were significantly higher in the intervention group (35.5 ng/mL vs 18.8 ng/mL). Nonetheless, C-ACT scores (the primary outcome) did not differ significantly between the groups, with median scores of 25 in both (a score of at least 19 indicates well-controlled asthma). Nor was there a significant difference between the 2 groups in FEV₁ and FeNO levels. Eleven children had exacerbations (4 in the intervention group and 7 in the placebo group); none required emergency visits or hospitalization. The 2 groups did not differ in the number of exacerbations, emergency visits, and hospital admissions. Systemic steroids were given to 4 participants in the intervention group, 7 in the placebo group.

Thoughts from Dr. Farber

We are still searching for simple interventions for asthma and for areas in which vitamin D supplementation may be helpful. This does not appear to be such an area. Nevertheless, supplementation is a good idea for many children. Although it did not affect asthma control, vitamin D levels were low in the placebo group.

Reference

1. Thakur C, Kumar J, Kumar P, Goyal JP, Singh K, Gupta A. Vitamin-D supplementation as an adjunct to standard treatment of asthma in children: a randomized controlled trial (ViDASTA Trial). Pediatr Pulmonol. 2021;56(6):1427-1433. doi:10.1002/ppul.25287