Download BONSENSE PDF. Many consumers are lured by the advertised benefits of strontium for bone health. Supplements are increasingly available over the counter and through the Internet. Strontium is a trace element found in seawater and soil and is similar to calcium. A prescription form of strontium (the ranelate salt), known as Protelos™, is currently approved in Europe for the treatment and prevention of osteoporosis because it has been shown to reduce fracture risk. Strontium ranelate has not been approved in the U.S. The forms of strontium available over-the-counter in the U.S. or on the Internet are usually strontium citrate or strontium chloride. These forms are different from the ranelate compound and there have been no studies showing that they are safe or effective.