title: Dietary vitamin D dose-response in healthy children 2 to 8 y of age: a 12-wk randomized controlled trial using fortified foods.
abstract: BACKGROUND
  Vitamin D is fundamental for bone health. A high proportion of Canadian 2- to 8-y-olds do not meet the Estimated Average Requirement (EAR) of 400 IU/d.
  
  
  OBJECTIVE
  The objective was to determine whether vitamin D intakes consistent with the EAR or Recommended Dietary Allowance (RDA), through fortification of additional dairy products, would result in higher vitamin D status in young children.
  
  
  METHODS
  Participants aged 2-8 y (n = 77; Montreal, Canada) were randomly assigned to 1 of 3 dietary vitamin D targets (control; EAR: 400 IU/d; or RDA: 600 IU/d) for 12 wk (January to April 2014). Anthropometric measurements, demographic characteristics, dietary intakes, fasting serum parathyroid hormone, 25-hydroxyvitamin D [25(OH)D], and ionized calcium were compared by using mixed-model ANOVA.
  
  
  RESULTS
  Participants' mean ± SD age was 5.1 ± 1.9 y; 54.5% were boys with body mass index z scores of 0.50 ± 0.85. Compliance was 85% overall. No differences were observed in baseline dietary vitamin D intakes or serum 25(OH)D. At 12 wk, the EAR and RDA groups had significantly higher vitamin D intakes [median (IQR): control, 227 (184-305) IU/d; EAR, 410 (363-516) IU/d; and RDA, 554 (493-653) IU/d; P < 0.05] and serum 25(OH)D concentrations (control: 55.8 ± 12.3 nmol/L; EAR: 64.1 ± 10.0 nmol/L; and RDA: 63.7 ± 12.4 nmol/L; P < 0.05) than the control group. Ninety-six percent of children in the EAR and RDA groups and 67% of the control group had 25(OH)D concentrations ≥50 nmol/L.
  
  
  CONCLUSIONS
  Increasing the vitamin D intakes of young children through fortification of alternative dairy products results in significantly higher serum concentrations of 25(OH)D and a significantly greater proportion of children with serum 25(OH)D ≥50 nmol/L during periods of minimal ultraviolet B radiation exposure. This trial was registered at clinicaltrials.gov as NCT02097160 and had Health Canada Temporary Marketing Authorization Letters for both products (TM-13-0432 and TM-13-0433).
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Sainte Anne de Bellevue, Quebec, Canada;
authors.forename: Neil R
authors.initials: NR
authors.lastname: Brett
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Sainte Anne de Bellevue, Quebec, Canada;
authors.forename: Paula
authors.initials: P
authors.lastname: Lavery
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Sainte Anne de Bellevue, Quebec, Canada;
authors.forename: Sherry
authors.initials: S
authors.lastname: Agellon
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Sainte Anne de Bellevue, Quebec, Canada;
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Vanstone
authors.affiliation: Applied Health Research Centre, Li Ka Shing Knowledge Institute of St. Michael's Hospital, Department of Pediatrics, University of Toronto, Toronto, Canada; and.
authors.forename: Jonathon L
authors.initials: JL
authors.lastname: Maguire
authors.affiliation: Shriners Hospital for Children, Department of Pediatrics, McGill University, Montreal, Canada.
authors.forename: Frank
authors.initials: F
authors.lastname: Rauch
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Sainte Anne de Bellevue, Quebec, Canada; hope.weiler@mcgill.ca.
authors.forename: Hope A
authors.initials: HA
authors.lastname: Weiler
mesh_terms: D002170:Canada; D002648:Child; D002675:Child, Preschool; D003611:Dairy Products; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005260:Female; D005527:Food, Fortified; D006801:Humans; D008027:Light; D008297:Male; D064167:Recommended Dietary Allowances; D012621:Seasons; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood / Q000517:prevention & control*; D014815:Vitamins / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: dose response; food fortification; pediatric; randomized controlled trial; vitamin D