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The selection and prevalence of natural and fortified calcium food sources in the diets of adolescent girls

Rafferty K, Watson P, Lappe JM

Journal of nutrition education and behavior, 2011

149 participants

Abstract

OBJECTIVE: To assess the impact of calcium-fortified food and dairy food on selected nutrient intakes in the diets of adolescent girls.

DESIGN: Randomized controlled trial, secondary analysis.

SETTING AND PARTICIPANTS: Adolescent girls (n = 149) from a midwestern metropolitan area participated in randomized controlled trials of bone physiology from 1997 to 2008.

INTERVENTION: Subjects randomly assigned to a high-calcium (HC) diet supplying 1,500 mg calcium/d, or their usual diet (UC).

MAIN OUTCOME MEASURES: Dietary intake was assessed from 3-day food records and calcium intakes categorized by food source. Food group composites, representing calcium-fortified and dairy food categories, were examined for their relative nutrient contributions. Student t tests were used to evaluate differences in selected nutrient intakes between the 2 study groups.

RESULTS: Dairy food contributed 68% of the total mean 1,494 mg calcium/d in the HC group, and calcium-fortified food contributed 304 mg calcium. In the UC group, dairy food contributed 69% of the total mean 765 mg calcium/d and calcium-fortified food contributed 50 mg calcium. Nutrient profiles of the dairy composites differed significantly from the calcium-fortified composites (P < .05).

CONCLUSIONS AND IMPLICATIONS: Dairy food was the primary source of calcium selected by these adolescent girls; calcium-fortified food augmented calcium intakes.

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 149 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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