Fluoride or fluorine deficiency is a disorder which may cause increased dental caries and possibly osteoporosis, due to a lack of fluoride in diet. Common dietary sources of fluoride include tea, grape juice, wine, raisins, some seafood, coffee, and tap water that has been fluoridated. The extent to which the condition truly exists, and its relationship to fluoride poisoning has given rise to some controversy. Fluorine is not considered to be an essential nutrient, but the importance of fluorides for preventing tooth decay is well-recognized, despite the effect is predominantly topical. Prior to 1981, the effect of fluorides was thought to be largely systemic and preeruptive, requiring ingestion. Fluoride is considered essential in the development and maintenance of teeth by the American Dental Hygienists' Association. Fluoride incorporates into the teeth to form and harden teeth enamels. This makes the teeth more acid resistant, as well as more resistant to cavity-forming bacteria. Caries-inhibiting effects of fluoride were first noticed 1902, when fluoride in high concentrations was found to stain teeth and prevent tooth decay.
Fluoride salts, particularly sodium fluoride (NaF), are used in the treatment and prevention of osteoporosis. Symptoms such as fractured hips in the elderly or brittle and weak bones may be caused by fluorine deficiency in the body. Fluoride stimulates bone formation and increases bone density; however, bone with excess fluoride content has an abnormal structure resulting in increased fragility. Thus, fluoride therapy results in large increases in bone mineral density but the effect on fracture rates, while positive, is small.
Disputes over the essential nature of fluorine date back to the 19th century, when fluorine was first observed in teeth and bones. In 1973, a trial claimed to have found reduced reproduction in mice fed on fluorine-deficient diets; however, a subsequent investigation found that this was likely due to an iron-deficient diet.
Role of fluoride
Fluoride increases resistance to the "demineralization of tooth enamel during attack by acidic bacteria". While essential for all individuals, fluoride's effects are most significant in children, as the fluoride is incorporated into their developing enamel. This in turn causes their teeth to become less prone to decay. Therefore, a relationship can be formulated, in that the more fluoride entering the body, the overall decline in the rate of decay.
The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the United States. For women ages 18 and older, the AI is set at 2.9 mg/day (includes pregnancy and lactation). For men, the value is 3.4 mg/day. For children ages 1–17 years, the AIs increase with age from 0.6 to 3.2 mg/day. These AIs are comparable to the U.S. AIs. The EFSA reviewed safety evidence and set an adult UL at 7.0 mg/day (lower for children).
See also
- Water fluoridation
- Public relations campaigns of Edward Bernays