Increase in bone calcification in young rats fed breads highly fortified with calcium

Breads were prepared with flour fortified with calcium (Ca) at four levels: 211 (U.S. enrichment standard), 446, 924, and 1,412 mg/100 g of flour. Cor responding diets prepared with these breads and fed to growing rats for fou r weeks provided 25 (diet A), 50 (diet B), 100 (diet C), and 150% (diet D) of their Ca requirement. After four weeks, the Ca content of the femurs of these rats had increased significantly as Ca in the diet increased up to 10 0% of requirement but not beyond. The increase in femur strength was signif icant only between diet A and diet B. Apparent Ca absorption increased as C a in the diet increased, but Ca absorbed from diet D was not retained any b etter than that absorbed from diet C. Overall, the data suggested that Ca i n highly fortified breads was well absorbed and retained, and that the rats ' Ca status early in life was greatly improved. Flour fortified with Ca up to the 924-mg level (4.4x the mandated enrichment level) had no adverse eff ect on bread quality. These breads can be labeled a "good source of" or "hi gh in" Ca.