The Healthspan Map · Nutrient

Fluoride

Linked to getting too little

Where a shortfall of Fluoride is linked — 2 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Fluoride	Eat enough of	Moderate	Established clinical	Fluoride hardens tooth enamel and inhibits/reverses caries; low fluoride raises dental-caries (tooth-decay) risk - community water fluoridation is a landmark public-health measure. Oral/dental health is grouped under the Digestive system (the mouth is the entrance to the GI tract), matching the added-sugars mapping.	NIH ODS / IOM DRI - Fluoride (opens in a new tab)
Fluoride	Eat enough of	Moderate	Established clinical	Fluoride hardens tooth enamel and inhibits/reverses caries; low fluoride raises dental-caries (tooth-decay) risk - community water fluoridation is a landmark public-health measure. Oral/dental health is grouped under the Digestive system (the mouth is the entrance to the GI tract), matching the added-sugars mapping.	NIH Office of Dietary Supplements — Fluoride (opens in a new tab)

Linked to getting too much

Where an excess of Fluoride is linked — 5 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Fluoride	Don't overdo	Moderate	Cohort / observational	Higher fluoride exposure (above recommended levels, e.g. high-fluoride water) is associated with lower IQ in children - evidence is observational and debated.	Fluoride-IQ literature (cross-sectional; NTP) (opens in a new tab)
Fluoride	Don't overdo	Strong	Established clinical	Chronic high fluoride (e.g. high-fluoride water ~5 mg/L) causes skeletal fluorosis - joint/bone pain, stiffness, calcified ligaments and restricted movement. The 10 mg UL is set on this.	NIH ODS / fluorosis studies (opens in a new tab)
Fluoride	Don't overdo	Strong	Established clinical	Chronic high fluoride (e.g. high-fluoride water ~5 mg/L) causes skeletal fluorosis - joint/bone pain, stiffness, calcified ligaments and restricted movement. The 10 mg UL is set on this.	Linus Pauling Institute — Fluoride (opens in a new tab)
Fluoride	Don't overdo	Moderate	Established clinical	Excess fluoride during tooth development causes dental fluorosis - enamel mottling and pitting. Dental/oral effects are grouped under the Digestive system for consistency with all other tooth-related mappings.	NIH ODS / fluorosis studies (opens in a new tab)
Fluoride	Don't overdo	Moderate	Established clinical	Excess fluoride during tooth development causes dental fluorosis - enamel mottling and pitting. Dental/oral effects are grouped under the Digestive system for consistency with all other tooth-related mappings.	NIH Office of Dietary Supplements — Fluoride (opens in a new tab)