title: Vitamin D intake among young Canadian adults: validation of a mobile vitamin D calculator app.
abstract: OBJECTIVE
  To establish the validity and reproducibility of the dietary component of a mobile vitamin D calculator app.
  
  
  METHODS
  Participants entered their dietary intake into the Vitamin D Calculator app on 3 recording days over 1 month and underwent subsequent 24-hour dietary recalls.
  
  
  RESULTS
  There were 50 adults (25 female), aged 18-25 years (mean, 22 ± 2 years). Paired-samples t tests tested for significant differences (P < .05) in mean vitamin D and calcium intake between the app and dietary recalls; Bland-Altman plots assessed agreement between the 2 measures. Intra-class correlations and Wilcoxon signed-rank tests assessed reproducibility of intakes estimated by the app. Mean vitamin D (n = 50) and calcium (n = 48) intakes and risk classifications did not differ significantly between the 2 measures (P > .05).
  
  
  CONCLUSIONS
  The Vitamin D Calculator app is a valid classification measure for dietary vitamin D and calcium intake. This tool could be used by the general public to increase awareness and intake of these nutrients.
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada. Electronic address: sgoodm01@uoguelph.ca.
authors.forename: Samantha
authors.initials: S
authors.lastname: Goodman
authors.affiliation: Department of Psychology, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Barbara
authors.initials: B
authors.lastname: Morrongiello
authors.affiliation: Department of Family Relations and Applied Nutrition, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Janis
authors.initials: J
authors.lastname: Randall Simpson
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Kelly
authors.initials: K
authors.lastname: Meckling
mesh_terms: D000293:Adolescent; D000328:Adult; D002136:Calcium, Dietary; D002170:Canada / Q000453:epidemiology; D015930:Diet Records; D005260:Female; D006801:Humans; D008297:Male; D063731:Mobile Applications; D015596:Nutrition Assessment; D015203:Reproducibility of Results; D012648:Self Care; D014807:Vitamin D; D055815:Young Adult
chemical_list: D002136:Calcium, Dietary; D014807:Vitamin D
keywords: calcium; mobile applications; nutrition assessment; self-monitoring; vitamin D