Retention of Fluorine in the Skeleton of the Rat Receiving Different Levels of Fluorine in the Diet

Abstract

The storage of fluorine was determined in the femurs of rats fed three diets containing different amounts of naturally occurring dietary fluorine. On diets containing 3 p.p.m. of fluorine or less the concentration of fluorine decreased after about 75 days of age. Diets containing about 8 p.p.m. of fluorine appeared to permit the skeleton to acquire increasing concentrations of fluorine. Females had lower concentrations of fluorine in their femurs as long as the concentration was increasing, but after the concentration had begun to decrease the males had lower concentrations. This was observed in animals fed ad libitum and in those in which the males were restricted to the same food intake as the females. The sexual difference may be dependent upon the rate of skeletal growth.