Iodine in the body was highlighted in the recent Japanese earthquake. With the Fukishima nuclear power station clearly leaking, radioactive Iodine was released into the sea water. This led to fears that marine organisms would ingest the iodine, it would move up the food chain and bioaccumulate in humans in the thyroid gland.
These fears were put down as the radioactive iodine in question has a very short half life and it was felt that the isotope would have decayed sufficiently by the time it potentially reached humans.
However, there is also an exclusion zone around the nuclear plant. This is to protect people from the radioactive fallout which would also include radioactive iodine. The effect of this iodine on the body would be more significant as it would not be subjected to the delay experienced in iodine in sea food.
In dietry terms, Iodine is considered a trace element. It is ingested as Iodide, I–.Its role in the body is that it is part of thyroxine and triiodothyronine. These are hormones produced in the thyroid gland. These hormones are required by the body to maintain and regulate the bodies metabolic rate.
A deficiency of iodine in the diet leads to fatigue, goitre, weight gain and depression.