Dietary fluoride prevents phosphorus-induced nephrocalcinosis in female rats.

The effect of dietary fluoride (F) on nephrocalcinosis was studied in young, female rats. Nephrocalcinosis was induced by a diet rich in phosphorus (P). F in the diet effectively counteracted P-induced nephrocalcinosis in a dose-dependent fashion. The feeding of increasing amounts of F caused decreasing calcium (Ca) and F concentrations in kidney. This suggests that the amount of Ca in kidney determines F accumulation in this organ, rather than F intake. Increasing amounts of F in the diet caused increasing rates of urinary and fecal excretion and whole-body retention of F. Dietary F did not influence urinary and fecal excretion and plasma concentrations of Ca, magnesium (Mg), and P. The metabolic basis for the protective effect of F against the development of nephrocalcinosis remains to be established.