title: Vitamin D3 supplementation and upper respiratory tract infections in a randomized, controlled trial.
abstract: BACKGROUND
  Randomized controlled trials testing the association between vitamin D status and upper respiratory tract infection (URTI) have given mixed results. During a multicenter, randomized controlled trial of colorectal adenoma chemoprevention, we tested whether 1000 IU/day vitamin D(3) supplementation reduced winter episodes and duration of URTI and its composite syndromes, influenza-like illness (ILI; fever and ≥2 of sore throat, cough, muscle ache, or headache) and colds (no fever, and ≥2 of runny nose, nasal congestion, sneezing, sore throat, cough, swollen or tender neck glands).
  
  
  METHODS
  The 2259 trial participants were aged 45-75, in good health, had a history of colorectal adenoma, and had a serum 25-hydroxyvitamin D level ≥12 ng/mL. They were randomized to vitamin D(3) (1000 IU/day), calcium (1200 mg/day), both, or placebo. Of these, 759 participants completed daily symptom diaries. Secondary data included semiannual surveys of all participants.
  
  
  RESULTS
  Among those who completed symptom diaries, supplementation did not significantly reduce winter episodes of URTI (rate ratio [RR], 0.93; 95% confidence interval [CI], .79-1.09) including colds (RR, 0.93; 95% CI, .78-1.10) or ILI (RR, 0.95; 95% CI, .62-1.46), nor did it reduce winter days of illness (RR, 1.13; 95% CI, .90-1.43). There was no significant benefit according to adherence, influenza vaccination, body mass index, or baseline vitamin D status. Semiannual surveys of all participants (N = 2228) identified no benefit of supplementation on ILI (odds ratio [OR], 1.14; 95% CI, .84-1.54) or colds (OR, 1.03; 95% CI, .87-1.23).
  
  
  CONCLUSIONS
  Supplementation with 1000 IU/day vitamin D(3) did not significantly reduce the incidence or duration of URTI in adults with a baseline serum 25-hydroxyvitamin D level ≥12 ng/mL.
authors.affiliation: Department of Community and Family Medicine, Section of Biostatistics and Epidemiology.
authors.forename: Judy R
authors.initials: JR
authors.lastname: Rees
authors.forename: Kristy
authors.initials: K
authors.lastname: Hendricks
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Barry
authors.forename: Janet L
authors.initials: JL
authors.lastname: Peacock
authors.forename: Leila A
authors.initials: LA
authors.lastname: Mott
authors.forename: Robert S
authors.initials: RS
authors.lastname: Sandler
authors.forename: Robert S
authors.initials: RS
authors.lastname: Bresalier
authors.forename: Michael
authors.initials: M
authors.lastname: Goodman
authors.forename: Roberd M
authors.initials: RM
authors.lastname: Bostick
authors.forename: John A
authors.initials: JA
authors.lastname: Baron
mesh_terms: D000368:Aged; D002762:Cholecalciferol / Q000627:therapeutic use*; D015179:Colorectal Neoplasms / Q000382:microbiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D012141:Respiratory Tract Infections / Q000097:blood / Q000188:drug therapy / Q000517:prevention & control*; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D
keywords: randomized controlled trial; upper respiratory tract infection; vitamin D