Urinary fluoride excretion in small children following short‐term fluoride supply with tablets or domestic salt

– Urinary fluoride (F) excretion has been studied in small children, with some comparisons with adults, following ingestion of F tablets or fluoridated salt (F‐salt) containing 500 mg F/kg NaCl. 24‐h urinary F in 7‐ to 8‐year‐old children in an institution and in 2‐ to 12‐year‐old children in families rapidly increased to average levels of about 0.85 and 0.55 parts/10 6 , respectively, when the children had their meals spiced with F‐salt. Children in families also showed significantly elevated urinary F excretion with two F‐salted meals a day but not with one a day. After taking 0.5 mg F in the form of NaF tablets a group of children without previous F supply attained within 1 d a 24‐h urinary F concentration which was about the same as that in children who had been taking caries‐preventive tablet doses for years. The percentage of a single F dose excreted in the urine within 4 h after the ingestion of F tablets or an F‐salted standard meal was about the same in preschool children and middle‐aged adults. F quantities of the order 1.5–2 mg could be ingested by a child eating a meal comprising strongly F‐salted dishes, and the urine could reach concentrations around 3 parts/10 6 F during the following 2–4 h. The results obtained support the concept that domestic salt containing about 500 parts/10 6 F is suitable for clinical testing on a larger scale under Swedish conditions. Calculations of F supplies to children aged 2 months‐7 years with different diets and water and salt F contents are presented as digrams.