at iodine is it a Trace element , which is essential and non-metallic. It is subordinate to the halogens and has many important functions for the human organism.
Iodine is almost never found in its pure form and hardly ever occurs in nature. Instead, it designates a solid which, when heated, vaporizes into a violet-colored gas, which explains the primordial name "Ioeides" from ancient Greek.
Those stands for violet colored or violet. Just like other essential substances, the trace element cannot be produced independently by the body, but it must be found in every healthy organism.