Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Can Vitamin D Prevent Asthma Exacerbations?

Lancet Respir Med; ePub 2017 Oct 3; Jolliffee, et al

Vitamin D supplementation reduces the rates of asthma exacerbations requiring treatment with systemic corticosteroids, according to a recent study. The systematic review and meta-analysis of individual participant data included 483 unique studies, 8 of which were eligible randomized controlled trials with 1,078 participants. This included double-blind, placebo-controlled, RCTs of vitamin D3, or vitamin D2 supplementation in persons with asthma that reported incidence of asthma exacerbation, published between database inception and October 26, 2016. Researchers found:

  • Vitamin D supplementation reduced the rate of asthma exacerbation requiring treatment with systemic corticosteroids among all participants (adjusted incidence rate ratio, 0.74).
  • There were no significant differences between vitamin D and placebo in the proportion of participants with at least 1 exacerbation or time to first exacerbation.
  • Subgroup analyses of the rate of asthma exacerbations treated with systemic corticosteroids revealed that protective effects were seen in participants with baseline 25(OH)D of < 25 nmol/L (aIRR 0.33, p=0.046), but not in participants with higher baseline 25(OH)D levels.


Jolliffe DA, Greenberg L, Hooper RL, et al. Vitamin D supplementation to prevent asthma exacerbations: a systematic review and meta-analysis of individual participant data. [Published online ahead of print October 3, 2017]. Lancet Respir Med. doi:10.1016/S2213-2600(17)30306-5.


Results of this study are consistent with that of a related Cochrane review which concluded that in double-blind, placebo-controlled RCTs in both children and adults, vitamin D supplementation reduced the rate of asthma exacerbations requiring treatment with systemic corticosteroids by 36%.1 The current meta-analysis furthers that evidence by showing that the beneficial effect of vitamin D occurred in those with asthma who had low vitamin D levels prior to treatment. In that group, there was a decrease of 67% in the incidence of asthma exacerbations with vitamin D supplementation. This is information that we can use tomorrow with our patients. It makes sense to check a vitamin D level n patients with asthma who have had exacerbations; if it is low, then supplement with vitamin D. —Neil Skolnik, MD

  1. Martineau AR, Cates CJ, Urashima M, et al. Vitamin D for the management of asthma. Cochrane Database Syst Rev. 2016;CD011511.

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