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 …