title: Vitamin D supplementation in pregnancy, prenatal 25(OH)D levels, race, and subsequent asthma or recurrent wheeze in offspring: Secondary analyses from the Vitamin D Antenatal Asthma Reduction Trial.
abstract: BACKGROUND
  Nutrient trials differ from drug trials because participants have varying circulating levels at entry into the trial.
  
  
  OBJECTIVE
  We sought to study the effect of a vitamin D intervention in pregnancy between subjects of different races and the association between 25-hydroxyvitamin D3(25[OH]D) levels in pregnancy and the risk of asthma/recurrent wheeze in offspring.
  
  
  METHODS
  The Vitamin D Antenatal Asthma Reduction Trial is a randomized trial of pregnant women at risk of having children with asthma randomized to 4400 international units/d vitamin D or placebo plus 400 international units/d vitamin D. Asthma and recurrent wheezing until age 3 years were recorded.
  
  
  RESULTS
  African American (AA) women (n = 312) had lower initial levels of 25(OH)D (mean [SD], 17.6 ng/mL [8.3 ng/mL]) compared with non-AA women (n = 400; 27.1 ng/mL [9.7 ng/mL], P < .001). No racial difference was found from vitamin D supplementation in pregnancy on asthma/recurrent wheezing in offspring (P for interaction = .77). Having an initial level of greater than 30 ng/mL and being randomized to the intervention group was associated with the lowest risk for asthma/recurrent wheeze by age 3 years compared with having an initial level of less than 20 ng/mL and receiving placebo (adjusted odds ratio, 0.42; 95% CI, 0.19-0.91).
  
  
  CONCLUSIONS
  We did not find differences between AA and non-AA mothers in the effect of maternal vitamin D supplementation and asthma/recurrent wheeze in offspring at 3 years. Maternal supplementation of vitamin D, particularly in mothers with initial 25(OH)D levels of greater than 30 ng/mL, reduced asthma/recurrent wheeze in the offspring through age 3 years, suggesting that higher vitamin D status beginning in early pregnancy is necessary for asthma/recurrent wheeze prevention in early life.
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass; COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Helene M
authors.initials: HM
authors.lastname: Wolsk
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Harshfield
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass.
authors.forename: Nancy
authors.initials: N
authors.lastname: Laranjo
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass; Harvard Medical School, Boston, Mass.
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Carey
authors.affiliation: Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, Mass.
authors.forename: George
authors.initials: G
authors.lastname: O'Connor
authors.affiliation: Department of Pediatrics, Boston Medical Center, Boston, Mass.
authors.forename: Megan
authors.initials: M
authors.lastname: Sandel
authors.affiliation: Division of Pediatric Allergy, Immunology and Pulmonary Medicine, Department of Pediatrics, Washington University School of Medicine and St Louis Children's Hospital, St Louis, Mo.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Strunk
authors.affiliation: Division of Pediatric Allergy, Immunology and Pulmonary Medicine, Department of Pediatrics, Washington University School of Medicine and St Louis Children's Hospital, St Louis, Mo.
authors.forename: Leonard B
authors.initials: LB
authors.lastname: Bacharier
authors.affiliation: Department of Allergy and Research evaluation, Kaiser Permanente Southern California, San Diego and Pasadena, Calif.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Zeiger
authors.affiliation: Department of Allergy and Research evaluation, Kaiser Permanente Southern California, San Diego and Pasadena, Calif.
authors.forename: Michael
authors.initials: M
authors.lastname: Schatz
authors.affiliation: Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Hollis
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass; Harvard Medical School, Boston, Mass.
authors.forename: Scott T
authors.initials: ST
authors.lastname: Weiss
authors.affiliation: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Mass; Harvard Medical School, Boston, Mass. Electronic address: augusto.litonjua@channing.harvard.edu.
authors.forename: Augusto A
authors.initials: AA
authors.lastname: Litonjua
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American; D001249:Asthma / Q000453:epidemiology* / Q000517:prevention & control; D002112:Calcifediol / Q000097:blood; D002675:Child, Preschool; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology* / Q000517:prevention & control; D012008:Recurrence; D012135:Respiratory Sounds; D012306:Risk; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D014807:Vitamin D; D002112:Calcifediol
keywords: Vitamin D; allergy; asthma; prenatal; randomized controlled trial