Fluoride

Fluoride is a trace mineral naturally found in small amounts in a variety of foods. It is most recognized for its role in preventing and reversing dental caries and building strong teeth and bones. [1] Most fluoride is absorbed in the gut and stored in bones and teeth. Unabsorbed fluoride is excreted in urine. Children absorb fluoride more efficiently than adults, as their teeth and bones are rapidly forming.

Recommended Amounts

AI: There is not a Recommended Dietary Allowance for fluoride as nutritional requirements have not been established. However, adequate intakes (AI), or the amount assumed to ensure adequate nutrition, have been established for adults 19+ years at 4 mg a day for men and 3 mg for women. For women who are pregnant or lactating, the AI is 3 mg.

UL: The Tolerable Upper Intake Level (UL) for fluoride for all adults 19+ years of age and pregnant and lactating women is 10 mg daily; a UL is the maximum daily intake unlikely to cause harmful effects on health.

Fluoride and Health

Food Sources

Trace amounts of fluoride are found naturally in various foods, though people obtain most fluoride from fluoridated water and toothpastes. Brewed black tea and coffee naturally contain fluoride as the plants absorb the mineral in soil. Shellfish may contain fluoride that collects in their shells and muscles.

• Brewed black tea and coffee
• Fluoridated water
• Canned shellfish like shrimp and blue crab
• Oatmeal
• Raisins
• Potatoes
• A look at the controversy of fluoridated water
  Questions have been posed about the continued need for and safety of community fluoridated water, with concerns about ingesting excessive fluoride and potential negative health effects. Adding fuel to the fire, a top medical journal labeled fluoride as a human developmental neurotoxicant, placing it in the same category as toxic metals like lead and arsenic. [12]One known condition is dental fluorosis, in which the teeth of children exposed to excess fluoride develop permanent white spots on the tooth’s surface. Most cases are mild and, although changing the tooth’s appearance, do not affect tooth function or have negative health effects.A more contentious claim suggests that ingesting excess fluoride (largely from community fluoridated water) causes cognitive deficits and lowered intelligence in children. A comprehensive review of epidemiological, animal, and laboratory studies found an association, but the authors noted various confounding factors present that may have contributed to cognitive deficits, including low birth weight, socioeconomic status, and exposure to other neurotoxic chemicals. [11] An association was also found in animal studies between deficits in learning and memory when rats were given more than 100 mg per liter of fluoride. However, these high levels were considered toxic and a likely contributor to the deficits. Lower fluoride amounts of 2-50 mg per liter in other animal studies are still much higher than that provided in community fluoridated water. A widely cited analysis of cross-sectional studies of children that found lowered IQ in those exposed to fluoridated water was criticized for lack of data, use of unvalidated IQ tests, and confounders, such as the children’s exposure to other toxic substances (lead, mercury) from living in highly polluted areas. [12] Most of these studies included rural populations experiencing low income that also likely had lower access to healthcare and nutritious diets. Another criticism is that cross-sectional observational studies are not intended to make direct cause-and-effect conclusions. Some scientists argue that IQs overall have increased since introducing community fluoridated water, although improved education and early intervention services are other likely contributors. [11]

  In adults, there is concern of the accumulation of excess fluoride in bones that may increase the risk of fractures. Research has shown mixed results, from a positive association, to no association, to even a protective effect of fluoride. A meta-analysis looking at 13 cohort studies did not find an association of exposure to fluoride from drinking water (ranging from 7 to 44 years) and an increased risk of hip fractures in older adults. [13] The authors noted potential confounding factors, such as increased calcium supplement use in this age group, which can decrease fluoride absorption. Bone formation also decreases with age, so less fluoride is absorbed and needed by bone tissue. In contrast, a cohort study published in 2021 looking at the association of fractures in postmenopausal women and fluoride as measured in urine and dietary intakes found higher rates of hip fractures when comparing the highest to lowest intakes of fluoride and urinary fluoride. The mean dietary intake was about 2 mg daily that included drinking water fluoridated at about 1 mg per liter. [14] With these inconclusive findings, additional large studies are needed in this area.

  There also remains a question of potential health risks with specific conditions, such as kidney disease in which people may not be able to excrete excess fluoride if exposed, increasing the risk of toxicity. There is also a risk of fluoride causing chronic kidney disease (CKD), as shown in studies of people exposed to excessive fluoride due to unusually high levels in the groundwater who develop CKD. [15,16] It is noted that these scenarios are not seen with community fluoridated water but where local water naturally contains excessive levels. Still, fluoride is required by the body in only trace amounts, and it is unclear of the effects of lifetime exposure to fluoride through community water and fluoride-supplemented dental products in specific situations such as CKD. More research is needed to see the health effects of fluoride in people with CKD and if they may benefit from limiting the ingestion of fluoride.

  Water has been fluoridated in the U.S. and in other countries since the 1940s, and research to date has not shown negative health consequences for the general population that outweigh its protective benefits. Because of the known risk of severe health problems in children and adults associated with dental caries, national health organizations such as the Centers for Disease Control and Prevention (CDC), the American Academy of Pediatrics (AAP) and the American Dental Association (ADA) continue to support the safety, effectiveness, and cost effectiveness of community fluoridated water. The current recommended amount is 0.7 mg of fluoride per liter of water, which helps to reduce the risk of caries but is also low enough to reduce the risk of developing fluorosis.

• Proper use of fluoridated toothpaste for children

  Our toothpaste guide helps ensure children get the right amount of fluoride for their age and oral health status.

  Use fluoridated toothpaste properly

  Use toothpaste that contains fluoride to brush your child’s teeth twice a day. Remember, toothpaste contains high amounts of fluoride. Because very young children may not have developed the ability to spit, they may swallow toothpaste when brushing. We recommend using the right amount of toothpaste for your child’s age. Follow these recommendations:

  Infants and toddlers age 0 to 3 (36 months)

  If your child is under 3 years old (0 to 36 months), you should consult a health professional to determine if your child is at risk of developing tooth decay. Children at risk, should have their teeth brushed by an adult using a minimal amount (rice-sized grain) of fluoridated toothpaste. 

  Children age 3 to 6

  An adult should always help children under age 6 brush their teeth and use only a small amount (small green pea-sized or 5 mm maximum) of fluoridated toothpaste.

  

  Figure – Text equivalent

  Children age 6 and older

  Once your child is 6 years old and has developed the ability to spit out the toothpaste, they are ready to start supervised tooth brushing using toothpaste that contains fluoride.

  Fluoride in drinking water

  We support community water fluoridation as an effective way to prevent tooth decay. It is universally accessible and provides benefits to all members of a community, regardless of their:

  • age
  • gender
  • income
  • ethnicity
  • education
  • access to oral health services
  • ability to afford oral hygiene supplies

  Community water fluoridation has been proven to be a safe, effective and equitable way to prevent and reduce tooth decay (including root decay) for people of all ages, from children to seniors.

  Learn more about the science of community water fluoridation:

  • Community water fluoridation programs: A health technology assessment.