TABLE 1.

Characteristics of the Vitamin D Antenatal Asthma Reduction Trial

Trial	N	Inclusion/exclusion criteria	Duration of supplementation	Follow-up	Supplementation
VDAART, double-blinded, multicenter RCT, United States (2009–2015)	806 paired pregnant women and their offspring included in the intent-to-treat analysis for the primary outcome of asthma or recurrent wheeze	Inclusion: parental asthma, allergy, or eczema Exclusion: maternal chronic disease	From 10–18 wks of gestation until birth	6 y of follow-up by quarterly telephone calls and annual visits to the clinic	Intervention (n = 405): 4000 + 400 IU/d Placebo (n = 401): 400 IU/d

Abbreviations: RCT, randomized controlled trial; VDAART, Vitamin D Antenatal Asthma Reduction Trial.