Fluoride exerts a biphasic action at the level of osteoblasts, on bone
mineral, on bone structure and function, and in the treatment of oste
oporosis. At low circulating concentrations, skeletal uptake of fluori
de is limited and the effects ave beneficial. Ar higher concentrations
and greater skeletal uptake, fluoride may cause the formation of abno
rmally mineralized bone of impaired quality. A new treatment program e
ntailing intermittent slow release sodium fluoride (SR-NaF) with conti
nuous calcium citrate may capture desirable qualities of fluoride with
out toxic effects, and be therapeutically efficacious in postmenopausa
l osteoporosis.