The bioavailability of magnesium (Mg) may be inhibited bycertain compounds in cereal based foods (fiber, phytate, protein, fat, and certain mineral elements such as calcium and phosphate). Bread fortified with Mg oxide was available based on femur Mg content using regression equations. One study demonstrated interference with Mg absorption when cellulose, hemicellulose, and pectin were added to dietary intake. Another study in which bread was fortified with Mg in wheat flour, defatted soy flour, and Mg carbonate did not result in any pattern of decreased bioavailability. (kbc)