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Setting Dietary Reference Intakes with the use of bioavailability data: calcium.
1US Department of Agriculture/Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, and Texas Children's Hospital, Houston, TX 77030, USA. sabrams@bcm.edu
The American Journal of Clinical Nutrition
|March 5, 2010
Summary
Establishing Dietary Reference Intakes (DRIs) for calcium requires understanding calcium absorption and retention, especially in children. Controlled studies are crucial, but challenging in young children, necessitating age-specific data for accurate DRI values.
Area of Science:
- Nutrition Science
- Human Physiology
Background:
- Dietary Reference Intakes (DRIs) for calcium are critical for public health, particularly for children's growth and development.
- Accurate DRI determination relies heavily on understanding the relationship between calcium intake, absorption, and retention.
Purpose of the Study:
- To review the methodologies and challenges in determining calcium absorption and retention for establishing DRIs.
- To emphasize the importance of controlled study conditions and age-specific data in children.
Main Methods:
- Evaluation of studies using dual-tracer stable isotopes, mass balance, and other isotopic methods.
- Discussion of the challenges in achieving controlled conditions, especially in pediatric populations.
- Consideration of other dietary factors like vitamin D, enhancers, and inhibitors of calcium absorption.
Main Results:
- Dual-tracer stable isotope methods are currently predominant for assessing calcium absorption and retention.
- Strict dietary monitoring and sample collection pose significant challenges in young children.
- For most healthy populations, other dietary factors do not significantly alter net calcium absorption for DRI establishment.
Conclusions:
- DRI values should aim for targeted calcium absorption/retention levels, maximizing intake within constraints.
- Data from the specific age and pubertal status being evaluated is essential, rather than interpolating from other age groups.
- Future research should focus on refining methods for controlled calcium balance studies in children to inform accurate DRIs.
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