An Algorithm to Assess Calcium Bioavailability from Foods

The recommended calcium intakes to meet calcium requirements at various ages are based on average population absorption values. Absorption is altered by physiology, the calcium load, and type of food. The calcium intake necessary, therefore, to meet requirements depends upon diet composition, through bioavailability.

The objectives of this study was to improve predictions of calcium bioavailability on the basis of the food matrix.

We modeled calcium absorption data from individual foods, beverages, and fortified foods that were determined with calcium isotopic tracers and compared with milk as a referent to adjust for physiologic differences of the host.

Data from 496 observations were modeled to develop a predictive algorithm for calcium bioavailability in adults on the basis of calcium load and oxalate and phytate loads, which represent the 2 main inhibitors of calcium absorption.

This algorithm will be helpful in assessing calcium availability from the food supply, for developing diets for individuals and research cohorts, and for designing policies and interventions to address inadequate calcium intake for populations.