Mineral Utilization in the Rat

Abstract

A total of 96 weanling male albino rats was used in a study of effects of Ca, P, lactose, and substitution of isolated soy protein for whole egg white protein on growth and mineral utilization of normal and of Zn-deficient animals. Dietary Ca decreased weight gain, Zn absorption, femur Zn concentration, Mg absorption and balance, percentage Ca absorption and balance and percentage P absorption. It increased milligrams of Ca and P retained, percentage femur ash, and percentage Fe absorbed. Dietary P increased kidney calcification, percentage P absorbed and milligrams of P retained, while decreasing percentage P balance. Substitution of soy protein for whole egg white protein affected (increased) weight gain only of animals fed Zn-deficient diets. It decreased concentration of femur ash Zn, Ca and P absorption and balance, Mg, Zn, and Fe absorption. It increased kidney calcification. Lactose increased kidney calcification, percentage femur ash, Ca absorption and balance and Mg absorption. The main effects cited above were influenced by strong interactions, particularly between Ca and soy protein, indicating that the Ca effects were greater in the presence of soy protein. This is of practical importance in the consideration of Ca effects on Zn utilization.