An investigation of fluoride protection against dietary induced osteoporosis in the rat.

The purpose of this study was to determine whether the accumulation of substantial levels of fluoride in the skeleton during bone formation would significantly reduce, or prevent, the occurrence of osteoporosis experimentally induced at a later time with a low mineral-containing diet. Male weanling rats were pretreated for 15 weeks with either 0 or 50 ppm F in their drinking water, followed by treatment for four to twelve weeks with diets either optimal or deficient in both Ca and P. Intake of the Ca and P deficient diet resulted in a progressive loss of bone mass (per unit volume of femur), with little effect on the remaining bone. High skeletal F offered no protective effect. Ca and P depletion caused a significant decrease in bone breaking strength but produced only slight reduction in percentage ash in bone. Fluoride offered little protection against either. Neither skeletal F nor dietary Ca and P levels influenced the concentration of Ca, P or Ca/P ratios in bone ash. Skeletal Mg levels were slightly lower in the Ca and P depleted rats; however, F treatment essentially eliminated this. Ca and P depletion resulted in higher F levels in both incisors and bone. We conclude that osteoporosis was produced by feeding the Ca and P deficient diet. High skeletal F did not prevent nor reduce the severity of this dietary-induced osteoporosis.