Fluoride is incorporated into the enamel of developing teeth. It strengthens the enamel, making it more resistant to the acid attack of decay-causing bacteria. Although it is important during tooth formation, the effect fluoride has on the enamel after the teeth have erupted has been shown to provide much greater benefit.

Primary teeth begin to develop in utero and are completely formed at birth, lying just under baby’s gum. Fluoride does not cross the placental barrier, so primary teeth derive no benefit during formation. Only trace amounts of fluoride are found in breast milk.

Permanent teeth begin to form at birth, so optimal intake of fluoride is important. Additional fluoride prescribed in a chewable tablet should take into consideration other sources of fluoride besides the home water supply. Excessive ingestion of fluoride prior to seven years of age could result in discoloration of the enamel of the permanent teeth. A decay risk assessment should be performed before any fluoride supplement is prescribed for a young child.

Fluoride tablets should be taken at bedtime after the teeth are brushed. Milk and food will decrease the absorption of fluoride in the stomach. Once the child can chew a tablet, vitamins and fluoride should be taken separately.

Well water should be tested for fluoride content before taking a fluoride supplement.

Bottled water may or may not contain fluoride. The amount of fluoride in bottled water may vary with the season of the year, the water table and the plant from which the water was obtained.

Large bottles of water that are delivered for use in the home may be ordered with fluoride added to the water.

Juices, tea and soft drinks may contain significant amounts of fluoride. White grape juice has the highest fluoride content.

Home water purifiers may or may not remove fluoride. Distillation units and reverse osmosis systems remove a significant amount of fluoride. The age of the filter system and filter may have an effect on the amount of fluoride removed.

Check the fluoride content of the water that is consumed in other areas by your child such as daycare, school or a caregiver’s home before giving supplemental fluoride.

Do not use toothpaste with fluoride until three years of age unless your child has experienced decay before three years of age. Use only a match-head size before five years of age. Children's toothpaste may contain the same amount of fluoride as toothpaste for adults.