Comparative Utilization of Dietary Sr 90 and Calcium by Developing Rat Fetus and Growing Rat

Summary and Conclusions

Continuous feeding experiments with rats on a Sr⁹⁰ labeled feed indicated that: (a) dietary calcium was utilized for bone growth by a factor of 3.6 over Sr⁹⁰; (b) about 28.6% of the fetal calcium was derived from maternal calcium; (c) dietary calcium was utilized for bone formation in the developing fetus by a factor of 5.1 over Sr⁹⁰; (d) this high factor for the fetus was accounted for on the basis that calcium and Sr⁹⁰ released from the maternal skeleton were deposited in the fetus with the same selectivity of 3.6 for calcium as was observed for the growing rat.