Fluoride is the ionic form of the abundant element fluorine. It occurs in soil, rocks, and water, and is naturally present in food and drink. About 99% of the fluoride in the body is bound to calcified tissues (bones and teeth), and the rest is in the blood. Despite its presence in the body, it’s debated whether fluoride is an “essential” mineral, and there are no set dietary guidelines for fluoride.[1] Fluoride is also found in many toothpastes and in some dietary supplements. While inadequate fluoride intake leads to tooth decay (dental caries), excessive intake can damage tooth enamel and cause other side effects. To prevent tooth decay, fluoridation of community water has been a practice since the 1960s in the United States.[1] Currently, about 30 Western countries have fluoridation policies, but less than half have active community water fluoridation.[2]
What is fluoride?
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•Last Updated: May 16, 2025
Fluoride is the ionic form of fluorine and is found in soil, rocks, water, and food; approximately 99% of fluoride in the body is associated with bones and teeth. Although it helps prevent tooth decay, excessive fluoride can harm tooth enamel, and its essentiality as a mineral is debated, which has led to varying fluoridation practices in different countries.