Kelp is an excellent source of iodine. Iodine, a non-metallic element, was discovered in 1811 extracted from seawater. Today, it is mostly extracted from the mineral compound caliche. In the body, the thyroid secretes a hormone called thyroxine. This is made up from four iodine atoms. Thyroxine is responsible keeping the muscles and organs working properly. It also regulates low body temperature by keeping it warm.