WASHINGTON (AP) — U.S. health regulators announced plans Tuesday to phase out fluoride-containing supplements sometimes used to strengthen children’s teeth, opening a new front in Health Secretary Robert F. Kennedy Jr.’s effort against a mainstay of dental care.

The Food and Drug Administration said it will conduct a scientific review of the products by late October with the aim of removing them from the market. It was not immediately clear whether the agency planned to formally ban the supplements or simply request that companies withdraw them.

The products targeted by the FDA are sometimes recommended for children and teens who are at increased risk of tooth decay or cavities because of low fluoride in their local drinking water. They usually require a prescription from a pediatrician or dentist. Fluoride-based tablets and lozenges are designed to be chewed or swallowed. Companies also sell drops for babies and infants.

FDA Commissioner Marty Makary said the products pose a risk when swallowed by children because they may interfere with healthy gut bacteria that are critical to digestion, immunity and other key bodily functions. He also referenced studies showing possible associations between excess fluoride intake and other problems, including decreased IQ.

Previous reviews by public health experts and dental professionals have not shown any serious health risks with the products.

As state and local governments begin removing fluoride from their water, the need for supplemental fluoride is expected to grow.

Officials in Utah — the first U.S. state to ban fluoride from drinking water — recently made fluoride supplements available without a prescription.

Fluoride strengthens teeth and reduces cavities by replacing minerals lost during normal wear and tear, according to the Centers for Disease Control and Prevention. In 1962, the agency set guidelines for how much should be added to water.

Kennedy, a former environmental lawyer, has called fluoride a “dangerous neurotoxin” tied to a range of health dangers. Last month, he announced a task force to scrutinize fluoride’s use, while at the same time saying he would order the CDC to stop recommending it.

A report last year by the federal government’s National Toxicology Program concluded that drinking water with more than twice the CDC’s recommended level was associated with lower IQs in kids. The study was based on research conducted in Canada, China, India, Iran, Pakistan and Mexico.

“Ending the use of ingestible fluoride is long overdue,” Kennedy said in a statement Tuesday. “This decision brings us one step closer to delivering on President Trump’s promise to Make America Healthy Again.”

An influential government health panel recommends fluoride supplements for children between the ages of six months and 5 years if they live in areas with low fluoridation levels. The U.S. Preventative Services Task Forces judged the recommendation to have “high certainty” of benefit, based on the available evidence.

A 2010 paper from the American Dental Association recommended supplemental fluoride for children up to 16 years old who are at high risk of cavities. The recommendation was based on a review of studies across different age groups. The most common side effect associated with the products is spotting or discoloration of the teeth, caused by extra fluoride.

The FDA regulates most dental products, including fluoride-containing toothpastes, supplements, mouthwashes and rinses.

In recent weeks those products have increasingly been targeted with lawsuits and legal actions.

Last week, Texas Attorney General Ken Paxton announced an investigation into the marketing of fluoride toothpastes by Colgate-Palmolive and Proctor and Gamble. A press release from his office described the companies’ promotions as “misleading, deceptive and dangerous.”

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