Calcium absorbability from milk products, an imitation milk and calcium carbonate

Whole milk, chocolate milk, yogurt, imitation milk, (prepared from dairy and nondairy products), cheese, and calcium carbonate were labeled with ⁴⁵Ca and administered as a series of test meals to 10 healthy postmonopausal women. Carrier Ca content of the test meals was held constant at 250 mg and subjects fasted before each meal. The absorbability of Ca from the six sources was compared by measuring fractional absorption by the double isotope method. The mean absorption values for all six sources were tightly clustered between 21 and 26% and none was significantly different from the others using one-way analysis of variance. We conclude that none of the sources was significantly superior or inferior to the others.