Lynch MF, Griffin IJ, Hawthorne KM, Chen Z, Hamzo M, Abrams SA - 33746 N - Am J Clin Nutr 2007 ; 85(3) : 750-4.
BACKGROUND: Few calcium balance data are available from young children on which to base dietary recommendations.OBJECTIVE: The objective of the study was to evaluate the relation between calcium intake and balance in healthy children aged 1-4 y consuming typical American diets. DESIGN: Subjects were assigned to a diet with nutrient intakes similar to those of their usual diet. Calcium absorption was assessed by using a dual-tracer stable-isotope technique. Endogenous fecal excretion was measured in a subset of children, and net calcium balance was calculated.RESULTS: Mean calcium intake was 551 mg/d (range: 124-983 mg/d), and mean (+/-SEM) calcium retention was 161 +/- 17 mg/d. Both linear and nonlinear modeling of balance data showed that a calcium intake of approximately 470 mg/d led to calcium retention of 140 mg/d, which is the amount that meets expected bone growth needs in children of this age. No evidence was found that calcium intakes of 800 to 900 mg/d reached the threshold intake beyond which no additional increase in calcium retention would occur. CONCLUSIONS: Bone growth needs in 1-4-y-old children following American diets are met by a daily calcium intake of approximately 470 mg/d, which suggests that the current Adequate Intake of 500 mg/d is close to the actual Estimated Average Requirement. The benefits and risks of higher calcium intakes consistent with threshold values should be evaluated in a controlled trial before those intakes could be used as a basis for dietary recommendations.