The United States Department of Agriculture determines recommended dietary allowances (RDA) for various vitamins and minerals. Although fluoride has been endorsed as a safe and effective method of preventing tooth decay, no RDA for fluoride has been established. The following are general guidelines for daily fluoride consumption (in milligrams [mg]) according to the National Institutes of Health (NIH):

Total daily consumption of fluoride includes fluoride from water and other beverages, food, fluoride supplements and the use of dental care products that contain fluoride. Many people typically consume 1 mg of fluoride per day from their drinking water, and less than 1 mg of fluoride per day from food sources. These levels may differ, depending on the level of fluoride in drinking water and to what extent nonfluoridated bottled water is consumed.

The ideal range of fluoride in drinking water is between 0.7 and 1.2 parts per million (ppm). To determine the level of fluoride in drinking water, a person may do the following:

• Contact the local water utility. They are required by the Environmental Protection Agency to publish fluoride levels in annual water quality reports.
  
  
• Test private well water. Tests should be performed once a year to check fluoride levels. The well owner can arrange for a testing laboratory to send the collection containers and analyze the samples.
  
  
• Contact the bottled water manufacturer. When bottled water is the primary source of drinking water, the manufacturer should be contacted for information about potential fluoride levels.

If drinking water has inadequate levels of fluoride, fluoride supplements may be used for children between the ages of 6 months and 16 years. This helps to strengthen permanent teeth while they are still forming. Before a child receives fluoride supplements, parents or caregivers should inform the dentist about all sources from which the child receives fluoride, including the level of fluoride in the drinking water. The concentration of fluoride in supplements ranges from 0.25 mg to 1 mg per day.

In areas where drinking water contains high levels of fluoride, fluoride may be filtered from the water at home. Some home filtering systems (e.g., reverse osmosis, distillation) remove significant amounts of fluoride from drinking water. However, filters that attach to a water faucet or are present in pitchers (e.g., charcoal or carbon filters, water softeners) do not generally remove fluoride. People using any of these systems can check with the manufacturer for information on the filter’s ability to remove fluoride. 

Dental products that contain fluoride (e.g., fluoride toothpaste and mouth rinse) play an important role in the prevention of tooth decay. Although they have higher concentration levels of fluoride than drinking water, they are not typically a major source of fluoride because they are consumed in very small amounts. Examples of fluoride levels in these products include:

Because of the higher concentration of fluoride in these products, a pea-sized dab of fluoride toothpaste provides the same amount of fluoride (0.25 mg) as an eight-ounce glass of 1 ppm fluoridated drinking water. In practical use, many people receive more fluoride from the water they drink than they do from dental care products. Water is consumed in greater quantities and much more often during the day than these products.

Any concerns about fluoride levels should be brought to the attention of a dentist or physician.

Parents or caregivers can help to prevent the consumption of high levels of fluoride or fluoride overdose in their children. Tips to help parents manage their child’s fluoride consumption include:

• Monitor fluoride levels in drinking water. If fluoride levels in drinking water are above 2 ppm, parents should use an alternate, nonfluoridated source of water for children under 8 years old or whose permanent teeth are still forming. This helps to prevent the risk of dental fluorosis. The local water district can provide information on fluoride levels in water.
  
  
• Supervise children using fluoride products. Parents should carefully supervise young children during dental hygiene. Children may swallow fluoride toothpaste or mouth rinse, accidentally ingesting more fluoride than intended. Children under 6 years should not use mouth rinses due to a tendency to swallow rather than spit them out. Fluoride toothpastes may be used in children over the age of 2 years. During brushing, parents can ensure that their children:
  
  
• • Avoid flavored toothpastes, which may encourage swallowing
    
  • Use only the amount of toothpaste necessary (pea-size)
    
    
• Keep all fluoride products out of reach of children. Preventing child access to fluoride products may help prevent accidental fluoride overdose. This includes fluoride toothpastes, mouth rinses and fluoride supplements.
  
  
• Do not stock up on fluoride supplements. Dentists usually do not prescribe more than a certain level of fluoride supplements at a time to prevent the risk of overdose should a child take all supplements at once. To avoid the risk of accidental overdose, parents should not stockpile supplements.
  
  
• Use supplements only in certain circumstances. Supplements should only be taken if they are prescribed by a dentist or physician  and children do not receive adequate levels of fluoride in their drinking water.
  
  
• Separate supplement and calcium consumption. Calcium products (e.g., milk) may interfere with the body’s ability to absorb fluoride. When children are taking fluoride supplements, foods or beverages containing calcium should be consumed hours before or after the supplements to avoid this interference.   

Although the issue has not been sufficiently studied, taking fluoride supplements during pregnancy does not appear to provide any significant prenatal advantage to children compared to fluoride intake after birth.