Fluoride — a naturally occurring mineral found in water, soil, air and various foods — helps prevent dental cavities and tooth decay.

An ingestible fluoride prescription drug product for children was pulled from the market on Tuesday after the Food and Drug Administration (FDA) said it was never approved. The products are known as fluoride tablets, according to NPR. These include drops or lozenges meant for children who don’t get fluoridated water to help prevent cavities.