What fluoride does
Fluoride is built into tooth enamel, making it more resistant to acid and decay. Small amounts are also stored in bones.
How much
Adults need roughly 3–4 mg a day.
Sources
- Fluoride toothpaste — the most important source for your teeth.
- Tea, both black and green — tea plants take up fluoride from the soil.
- Fluoridated tap water, depending on where you live.
- Small amounts in walnuts, grapes and other foods.
A note
Children should use only a pea-sized amount of fluoride toothpaste — too much fluoride while teeth are forming can cause white marks on the enamel.