What it does in the body
- Dental caries prevention (enamel strengthening)
- Tooth enamel remineralization
- Inhibition of bacterial acid production in plaque
- Bone mineralization (at physiological levels)
- Potential role in bone fracture resistance
How much you need (Daily Value)
| Group | Recommended | Source |
|---|---|---|
| Adult male | 4 mg (AI) | NIH/IOM |
| Adult female | 3 mg (AI) | NIH/IOM |
| Pregnancy | 3 mg (AI) | IOM |
| Children | 0.7 mg (1-3y), 1.0 mg (4-8y), 2-3 mg (9-18y) | NIH/IOM |
| Older adults | 4 mg (men), 3 mg (women) | NIH/IOM |
Richest food sources
| Food | Amount | Where |
|---|---|---|
| Fluoridated water | 0.7 mg per liter | Americas/Europe/Australia |
| Black tea (brewed) | 0.3-0.5 mg per 100ml | global |
| Canned crab | 0.21 mg per 100g | global |
| Raisins | 0.23 mg per 100g | global |
| Grape juice (white) | 0.15 mg per 100ml | global |
| Shrimp | 0.17 mg per 100g | coastal regions |
| Oatmeal (cooked with fluoridated water) | 0.11 mg per 100g | global |
| Potatoes (cooked with fluoridated water) | 0.08 mg per 100g | global |
If you don't get enough
Mild: Increased susceptibility to dental caries
Moderate: Higher rates of dental decay, especially in children during enamel formation
Severe: Severe dental caries, potentially impaired bone mineralization (debated)
Time to onset: Effects on dental caries develop over years. Benefits of adequate fluoride are most critical during tooth development (ages 0-8).
Too much
Upper limit: 10 mg/day (adults), 0.1 mg/kg/day dental fluorosis threshold in children
Dental fluorosis (cosmetic to severe pitting), skeletal fluorosis (joint stiffness, calcification of ligaments, osteosclerosis), GI symptoms with acute ingestion. Probably toxic dose (warrants emergency medical treatment): ~5 mg/kg body weight. Certainly lethal dose: approximately 5-10 g total ingested (32-64 mg/kg body weight).
How well you absorb it
80-90% from water (sodium fluoride), 50-80% from food depending on matrix
Helped by: Empty stomach (increases absorption speed), Acidic pH
Hindered by: Calcium (forms insoluble calcium fluoride), Magnesium, Aluminum-containing antacids, High-calcium foods when consumed simultaneously
Cooking & storage
Fluoride content of food increases when cooked with fluoridated water. Tea leaves accumulate fluoride from soil — brewed tea is a significant fluoride source. Non-stick (PTFE) cookware does not significantly contribute fluoride to food.
Nutrisize Health totals every nutrient from what you actually eat, against targets set for your age and sex, and flags what's short — across 4,995 foods, on your device.
