On Mar. 27, 2025, Utah become the first state to ban fluoride in public drinking water, over opposition from dentists and national health organizations who warn the move will lead to medical problems and disproportionately affect low-income communities.

Republican Gov. Spencer Cox signed legislation that bars cities and communities from deciding whether to add the mineral to their water systems.

Fluoride strengthens teeth and reduces cavities by replacing minerals lost during normal wear and tear, according to the U.S. Centers for Disease Control and Prevention.

Utah lawmakers who pushed for a ban said putting fluoride in water was too expensive. Cox, who grew up and raised his own children in a community without fluoridated water, compared it recently to being “medicated” by the government.

Out of the 484 Utah water systems that reported data in 2024, only 66 fluoridated their water, an Associated Press analysis showed. The largest was the state’s biggest city, Salt Lake City.

Utah in 2022 ranked 44th in the nation for the percentage of residents that receive fluoridated water, according to the data from the Centers for Disease Control and Prevention.

Fluoridation is considered the most cost-effective way to prevent tooth decay on a large scale. More than 200 million people in the U.S., or almost two-thirds of the population, receive fluoridated water through community water. The addition of low levels of fluoride to drinking water has long been considered one of the greatest public health achievements of the last century.