Spencer Cox signed legislation barring cities and communities from deciding whether to add the cavity-preventing mineral to their water systems. Water systems across the state must shut down their fluoridation systems by May 7.Kennedy praised Utah for emerging as "the leader in making America healthy again." Nearly two-thirds of the U.S. population gets fluoridated drinking water, according to CDC data. The addition of low levels of fluoride to drinking water was long considered one of the greatest public health achievements of the last century.About one-third of community water systems — 17,000 out of 51,000 across the U.S. — serving more than 60% of the population fluoridated their water, according to a 2022 CDC analysis. The agency currently recommends 0.7 milligrams of fluoride per liter of water.But over time, studies have documented potential problems.