Urinary fluoride levels of population groups consuming salts different in fluoride concentration.

The effect of urinary level of a prolonged consumption of table salts containing 200, 250 or 350 mg/kg of fluoride has been studied. Urinary F concentration was increasing with all the three kinds of salt. In the group of consumers using 200 and 250 mg F/kg salt the equilibrium has been reached, but the urinary F level was still below that observed in populations who are drinking water of 1 mg/l F concentration. The equilibrium in the 2--14-year age groups consuming 350 mg F/kg salt could not yet set in. It is concluded that even a mixture of 350 mg F/kg is not in excess of the optimum and is far from the tolerated limit. Thus, this latter mixture may be used for caries prevention in areas with F-deficient drinking water, although it may be still less than the optimum.