Definition
Fluoride occurs naturally in the body as calcium fluoride, found primarily in the bones and teeth.

Alternative Names
Diet - fluoride

Function
Small amounts of fluoride help reduce tooth decay. Fluoridation of water supplies helped reduce dental caries in children by 50 to 60%. Fluorides are also involved in the maintenance of bone structure. Low doses of fluoride salts can sometimes be used, under the supervision of a doctor, for the treatment of conditions that cause accelerated bone loss, such as menopause and prolonged immobility.

Food Sources
Fluoridated water and food prepared in that type of water will contain fluoride. Natural fluoride is present in the ocean as sodium fluoride, so most seafood contains some form of fluoride. Tea and gelatin also contain fluoride.

Side Effects
Fluoride deficiency may appear in the form of increased incidence of dental caries and unstable bones and teeth.

When there is a high amount of fluoride in the drinking water, a problem called chronic dental fluorosis can occur. The tooth enamel becomes dull and unglazed with some pitting (mottled enamel). At very high concentrations (over 2.5 parts per million) dark brown stains appear on the teeth. Although unsightly, these teeth rarely have any dental caries.

In addition, high fluoride intake (20 to 80 milligrams per day) over a period of many years can cause skeletal fluorosis, which causes the bones to be chalky and brittle.

Recommendations
There are no specific recommended dietary allowances for fluoride. Here are the estimated safe and adequate intake guidelines:

infants
0 to 6 months -- 0.1 to 0.5 milligrams
6 months to 1 year -- 0.2 to 1.0 milligrams
children
1 to 3 years -- 0.5 to 1.5 milligrams
4 to 6 years -- 1.0 to 2.5 milligrams
7 to 10 years -- 1.5 to 2.5 milligrams
adolescents (11+ years) -- 1.5 to 2.5 milligrams
adults -- 1.5 to 4.0 milligrams