Dietary vitamin D dose-response in healthy children 2 to 8 y of age: a 12-wk randomized controlled trial using fortified foods

作者：Brett Neil R; Lavery Paula; Agellon Sherry; Vanstone Catherine A; Maguire Jonathon L; Rauch Frank; Weiler Hope A^*

来源：American Journal of Clinical Nutrition, 2016, 103(1): 144-152.

DOI：10.3945/ajcn.115.115956

• dose response
• food fortification
• pediatric
• randomized controlled trial
• vitamin D

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.
Design: 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 nmol/L.
Conclusion: 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).

• 出版日期2016-1
• 单位McGill