Risk of fluorosis associated with infant formulas prepared with bottled water

The purpose of this study was to estimate fluoride (F) intake from infant formulas prepared with different brands of bottled water.

Fluoride concentrations in 4 samples of infant milk and soy-based formulas, commercially available in the United States, prepared with deionized water and 5 brands of bottled water, were determined after Hexamethyldisioxane (HMDS)-facilitated diffusion, in duplicate, using an F ion-specific electrode. Possible fluoride ingestion per killogram body mass was estimated, based on suggested volumes of formula consumption, for infants 1 and 12 months.

Fluoride concentrations ranged from 0.076 to 0.214 ppm and 0.092 to 1.053 ppm for formulas prepared with deionized and bottled water, respectively. When prepared with deionized water, none of the formulas provided an F intake above the suggested threshold for fluorosis (0.07 mg F/kg/day). However, when prepared with some brands of bottled water containing 0.623 and 0.839 ppm, all of them did provide it.

Some brands of bottled water usually marketed for infants and used to dilute infant formulas may increase fluoride concentrations beyond reccommended levels believed to lead to fluorosis.