The calcium bioavailability from unripening cheeses produced by high heat-acid coagulation of milk was the major purpose of this work. The cheeses may supply a significant portion of the calcium needs for humans because of their total calcium content (from 747 to 605.6 mg/100 g cheese) and satisfactory Ca/P ratio (from 1.55 to 1.85). High bioavailability of calcium from the cheeses, expressed as the apparent absorption (from 57.4 ±0.6 to 60.5 ±1.1%) and retention (from 52.0±1.1 to 52.2±0.6%) make these dairy products to be an important source of available calcium in the human diet.