Bioavailability of Fluoride Added to Baby Formula and Milk

The aim of the present study was to examine the bioavailability of fluoride (F) from some infant food products containing considerable amounts of F. Three different solutions containing 5 mg F were administered on three separate occasions to 4 young volunteers. They consisted of 500 ml of a 10 ppm F water solution, 500 ml milk containing 10 ppm F and 500 ml of a baby formula prepared with a 10 ppm F solution. Plasma F and urinary F levels were subsequently monitored for 15 h. Pharmacokinetic analysis of the data was performed and F bioavailability calculated. The results show that 72% of all F in the milk- and 65% of all F in the water-diluted baby formula were absorbed. Results from in vitro recovery studies demonstrated a 100% F recovery from milk and a 90% F recovery from baby formula. An explanation for the contradictory findings in the in vivo experiments is discussed.