In the body, most fluoride is contained in bones and teeth. Fluoride is necessary for the formation and health of bones and teeth.
(See also Overview of Minerals Overview of Minerals Minerals are necessary for the normal functioning of the body’s cells. The body needs relatively large quantities of Calcium Chloride Magnesium Phosphate read more .)
Fluoride deficiency can lead to tooth decay Cavities Cavities are decayed areas in the teeth, the result of a process that gradually dissolves a tooth’s hard outer surface (enamel) and progresses toward the interior. (See also Overview of Tooth... read more 
and possibly osteoporosis Osteoporosis Osteoporosis is a condition in which a decrease in the density of bones weakens the bones, making breaks (fractures) likely. Aging, estrogen deficiency, low vitamin D or calcium intake, and... read more 
. Consuming enough fluoride can make tooth decay less likely and may strengthen bones. The addition of fluoride (fluoridation) to drinking water that is low in fluoride or the use of fluoride toothpaste and supplements significantly reduces the risk of tooth decay. Fluoride applied to teeth (fluoride varnish) may be helpful to reduce early childhood tooth decay in areas of the world where fluoride toothpaste or fluoridation is not readily available.
