Robert F. Kennedy Jr. says Donald Trump will work to eliminate fluoride from drinking water nationwide if elected.

Kennedy, the former independent presidential candidate who dropped out of the race and endorsed Trump, said the order would come on Day 1 of the new administration. He said the Trump White House “will advise all US water systems to remove fluoride from public water.”

Fluoride strengthens teeth and reduces cavities by replacing minerals lost during normal wear and tear, according to the US Centers for Disease Control and Prevention. Adding low levels of fluoride to drinking water has long been considered one of the the greatest public health achievements of the last century.

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Kennedy, a prominent supporter of the rejected public health claims, made the statement on social media platform X.

Robert F. Kennedy Jr. and Republican presidential candidate former U.S. President Donald Trump shake hands during a campaign rally at the Desert Diamond Arena on Aug. 23, 2024, in Glendale, Arizona. (Photo by Rebecca Noble/Getty Images)

It was unclear whether Kennedy discussed Saturday’s post with Trump or his aides. The Trump campaign did not respond directly, and a spokesman for Kennedy did not respond when asked.

But the sudden and unexpected social media post over the weekend evoked the chaotic policymaking process that has defined Trump’s tenure in the White House, when he will issue policy statements on Twitter at almost any hour. It also underscored the concerns many experts have about Kennedy, who has long promoted debunked theories about vaccine safety that have implications for US public health.

In 1950, federal officials approved water fluoridation to prevent tooth decay and continued to promote it even after fluoride toothpaste brands hit the market a few years later. Although fluoride can come from many sources, drinking water is the main source for Americans, researchers say.

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Officials lowered their recommendation for fluoride levels in drinking water in 2015 to address a dental condition called fluorosis, which can stain teeth and had become more common in U.S. children.

In August, a federal agency determined “with moderate confidence” that there is a link between higher levels of fluoride exposure and lower IQ in children. The National Toxicology Program based its conclusion on studies involving fluoride levels at about twice the recommended limit for drinking water.

A federal judge later cited that study to order the US Environmental Protection Agency to continue regulating fluoride in drinking water. U.S. District Judge Edward Chen cautioned that he was not certain that the amount of fluoride commonly added to water was causing lower IQs in children, but concluded that growing research indicated an unreasonable risk that it might be. He ordered the EPA to take steps to reduce that risk, but did not say what those steps should be.

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What role Kennedy might have if Trump wins Tuesday remains unclear. Kennedy recently told NewsNation that Trump asked him to “reorganize” agencies, including the Centers for Disease Control and Prevention, the National Institutes of Health, the Food and Drug Administration and some agencies within the Department of Agriculture.

Trump frequently mentions having the support of Kennedy, a scion of a Democratic dynasty and the son of former Attorney General Robert Kennedy and grandson of President John F. Kennedy.

Trump said Saturday that he told Kennedy, “You can work on food, you can work on anything you want,” except oil policy.

“He wants health, he wants women’s health, he wants men’s health, he wants children, he wants everything,” Trump added.