Fluoride exerts a biphasic action at the level of osteoblasts, on bone mineral, on bone structure and function, and in the treatment of osteoporosis. At low circulating concentrations, skeletal uptake of fluoride is limited and the effects are beneficial. At higher concentrations and greater skeletal uptake, fluoride may cause the formation of abnormally mineralized bone of impaired quality. A new treatment program entailing intermittent slow release sodium fluoride (SR-NaF) with continuous calcium citrate may capture desirable qualities of fluoride without toxic effects, and be therapeutically efficacious in postmenopausal osteoporosis.