Effect of a Low Calcium Diet on Bone Crystallinity and Skeletal Uptake of Ca 45 in Rats. ∗

Summary

Chemical and X-ray diffraction analyses were performed on femurs of rats receiving a low (0.1%) and high (0.8%) calcium diet with (50 ppm) and without (0 ppm) fluoride supplementaton in the water. In addition, uptake of Ca⁴⁵ by the ends and shafts of tibia was determined. Bone crystal-linity (i.e., crystal size and/or perfection) was not affected by calcium intake, and the improvement in crystal texture produced by fluoride was the same for the high and low calcium groups. Skeletal uptake of radiocalcium was approximately 20 times higher in calcium deficient animals. Fluoride decreased slightly the uptake of radiocalcium.