John D. MacArthur
The amount of fluoride that infants should consume was determined 20 years ago by the Institute of Medicine (IOM) in its Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. The IOM could not determine a "Recommended Dietary Allowance" for fluoride, nor even a less stringent "Estimated Average Requirement." That's because:
The best the US and Europe could come up with was an "Adequate Intake" (AI) as the reference value for fluoride.
In other words, if we look into a kid's mouth and can't see any damaged tooth enamel, then that level of fluoride intake must be safe for the entire body. Adverse effects on the infant GI tract or developing brain were not considered.
Imagine if decades ago, teeth were used to gauge the toxicity of nicotine. Smoking advocacy groups would argue that the critical adverse effect of a smoking would be yellowing of one's teeth.
Unlike all other age groups, the data used to determine the AI of fluoride for nursing infants was based on actual biological evidence: the amount of fluoride consumed via mother's breast milk arguably the most accurate and reliable data available for determining the appropriate level of fluoride intake for newborns. "The AI is the intake by healthy breast-fed infants as obtained from average human milk nutrient composition and average milk volume." [IOM p. 48] For fluoride, human milk-fed infants receive 0.001 to 0.003 mg/kg/day. [IOM p. 301]
This amount of fluoride nursing infants receive from breast milk daily is extremely low averaging about 0.001 mg (1 microgram) of fluoride per kilogram of body weight. What's more, the fluoride concentration in breast milk is "relatively insensitive to differences in the fluoride concentrations of the mother's drinking water." [IOM p. 305] Even when a mother's fluoride intake is high, levels in her breast milk remain very low.
Breast Milk Promotes Fluoride Elimination
Breast milk also protects nursing infants from lead, another "developmental neurotoxicant" that the EPA's Neurotoxicology Division has found "substantial evidence" (highest category) for being "toxic to the developing mammalian nervous system." Even if a mother's intake is high in lead, her breast milk is very low in lead.
For formula-fed infants under one year old, if their drinking water is not fluoridated, their cumulative average intake of fluoride is 0.11 mg/kg/day. If their water is fluoridated, it's 0.20 mg/kg/day. [Erdal and Buchanan 2005] That is twice their Tolerable Upper Intake Level of fluoride which the IOM says is 0.10 mg/kg/day.
IOM: Institute of Medicine. Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington, DC: The National Academies Press, 1997. Chapter 8: Fluoride.
EFSA: European Food Safety Authority. Scientific opinion on dietary reference values for fluoride. EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). EFSA Journal 2013;11(8):3332.
Research Reports by John D. MacArthur