ABSTRACT
This study used young rats as the test model to examine the relative bioavailability (RB) of calcium (Ca) in breads fortified with five different Ca sources. These sources included two inorganic (Ca carbonate and Ca sulfate) and two organic (Ca citrate and Ca lactate) Ca sources, and a brandname Ca supplement. RB was assessed based on rats' femur Ca content and Ca absorption data. No differences of any physiological significance were observed in RB of Ca among the five sources tested. Compared to Ca carbonate (bioavailability arbitrarily set at 100%), RB of Ca in Ca sulfate was 105%, in Ca citrate 103%, in Ca lactate 102%, and in the Ca supplement 102%. This suggests that foods fortified with Ca carbonate or Ca sulfate, which are commonly used for this purpose, may be as good a source of utilizable Ca as more expensive Ca sources such as prescribed or nonprescribed Ca supplements.
