CEI Comments on Use of Orally Ingestible Unapproved Prescription Drug Products Containing Fluoride in the Pediatric Population

Dear Commissioner Makary,

The Competitive Enterprise Institute (CEI) submits these comments in favor of the private use of fluoride supplements for children. CEI is a nonprofit policy organization committed to promoting individual liberty, free enterprise, and limited government.

Studies generally show that in low concentrations such as those that prevail in the United States, fluoride produces minimal adverse effects. The request for comments on this topic singles out the effects of supplementary fluoride on minors of various ages and points to potential adverse effects that have been found primarily in adults related to the gut microbiome, IQ, liver function, etc. at very high concentrations.

More specifically, a careful review of each of these studies reveals that there is very little investigation into the question of concern—what is the effect of fluoride supplements given to children. Below, I provide a summary of each of the studies and the main takeaway.

“Does Fluoride Exposure Impact on the Human Microbiome?” is a review of the literature studying the effects of fluoride on microbiomes. It identified 22 studies that involved humans.  While some of these studies did include children, all but one of them were based on topical use of fluoride. The one study that did consider ingested supplements did not study its effects on IQ, kidney use, or the gut microbiome. Only one of the studies on animals considered ingestion at concentrations tantamount to what humans would experience, and it found that low levels of fluoride had no effect on the gut microbiome.

The study “Effect of Fluoride on Gut Microbiota: A Systematic Review” included only three studies on the effect of fluoride on humans, and a fourth on fecal samples. Of these, two of them were studies of fluorosis which requires a much higher concentration of fluoride than the supplements in question. The final study was of the use of a Fluorine-18-fluorodeoxyglucose (18F-FDG) tracer in positron emission tomography (PET). While 18F-FDG does contain fluorine, since it is primarily a glucose molecule, designed to be absorbed by the body, any effect it has on the gut microbiome cannot be considered probative, as it will be absorbed more readily than standard fluorine and may have an effect beyond what typical applications would have.