Dietary fluoride intake for fully formula-fed infants in New Zealand: impact of formula and water fluoride.
OBJECTIVE
A survey of the fluoride content of infant and toddler formulae available on the New Zealand market was conducted. Results were used to estimate the dietary fluoride intake for a fully formula-fed infant.


METHODS
Infant and toddler formulae were prepared according to manufacturers' instructions with fluoride-free water and analyzed for fluoride by a modification of the microdiffusion method of Taves. A proportion of samples were reanalyzed after reconstitution with water at fluoride concentrations of 0.7 and 1.0 mg/L. A stochastic model was used to estimate dietary fluoride intake.


RESULTS
The mean fluoride content of prepared infant formulae was 0.069 mg/L. When formulae were prepared with water of differing fluoride concentrations, the fluoride concentration was found to be a simple linear function of water fluoride concentration. Estimates of dietary fluoride intake for infants consuming formuae prepared with fluoride-free water were well below the upper level of intake (UL) for New Zealand and Australia (0.7 mg/day). At water fluoride concentrations of 0.7 and 1.0 mg/L the UL would be exceeded 30 and 93 percent of the time, respectively.


CONCLUSIONS
The fluoride content of water used to reconstitute infant formulae has a greater impact on fluoride intake of fully formula-fed infants than the fluoride content of the powdered infant formulae. Infants fully formula-fed on formulae prepared with optimally fluoridated water (0.7-1.0 mg/L) have a high probability of exceeding the UL for fluoride and are at increased risk of dental fluorosis.
Cressey
Peter
P
Food Safety Programme, Institute of Environmental Science and Research Ltd. Christchurch 8540, New Zealand. peter.cressey@esr.cri.nz
D002327:Cariostatic Agents / Q000008:administration & dosage*; D002675:Child, Preschool; D005459:Fluorides / Q000008:administration & dosage* / Q000009:adverse effects; D009050:Fluorosis, Dental / Q000209:etiology; D005504:Food Analysis; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry*; D009010:Monte Carlo Method; D009520:New Zealand; D012044:Regression Analysis; D014867:Water / Q000737:chemistry
D002327:Cariostatic Agents; D014867:Water; D005459:Fluorides