Iodine is too reactive to be in nature as an element. Iodine compounds are not common in the ground. There is a mineral called caliche that is found in dry deserts. It has iodate in it. Iodide is found in seawater. Kelp has quite large amounts of iodine in it. Iodine is one of the heaviest elements needed by living things. If people do not get enough of it, they get a disease known as goitre. Most salt has iodine in it, in the form of iodide or iodate. People can also take iodine pills to make sure we get enough.