Iodine is the molecule that is taken up by cells in the body. However, Iodine is a gas and is not very available in food and supplements. Instead, it is the iodide form that is more stable and can be consumed. In the body, Iodide converted into Iodine which is the active form.
http://articles.mercola.com/sites/articles/archive/2013/05/04/iodine-deficiency-affect-childs-brain-function.aspx
Good sources of iodine. Iodine is a trace element found in seawater, rocks and some types of soil. Good food sources include sea fish and shellfish. Iodine can also be found in plant foods, such as cereals and grains, but the levels vary, depending on the amount of iodine in the soil where the plants are grown.
http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Iodine.aspx
Isotopes: Twenty-three isotopes of iodine are known. Only one stable isotope is found in nature, I-127. Properties: Iodine has a melting point of 113.5°C, boiling point of 184.35°C, specific gravity of 4.93 for its solid state at 20°C, gas density of 11.27 g/l, with a valence of 1, 3, 5, or 7.
http://chemistry.about.com/od/elementfacts/a/iodine.htm
Iodine Deficiency. Iodine is an element that is needed for the production of thyroid hormone. The body does not make iodine, so it is an essential part of your diet. Iodine is found in various foods (see Table 1). If you do not have enough iodine in your body, you cannot make enough thyroid hormone.
http://www.thyroid.org/iodine-deficiency/
Iodine will bind to starch and color it deep blue. Although iodine is essential for proper nutrition, care is needed when handling the element, as skin contact can cause lesions and the vapor is highly irritating to the eyes and mucous membranes.
http://chemistry.about.com/od/elementfacts/a/iodine.htm
You should be able to get all the iodine you need by eating a varied and balanced diet. If you take iodine supplements, don't take too much, because this could be harmful. Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm.
http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Iodine.aspx
Insufficient dietary iodine leads to the formation of a goiter. A solution of iodine and KI in alcohol is used to disinfect external wounds. Potassium iodide is used in photography. Sources: Iodine is found in the form of iodides in seawater and in the seaweeds which absorb the compounds.
http://chemistry.about.com/od/elementfacts/a/iodine.htm
Hypothyroidism, which is one of the first ailments to develop in response to iodine deficiency, is indeed particularly troublesome during pregnancy. One 1999 study found that thyroid deficiency during pregnancy can lower your child's IQ by about seven points.
http://articles.mercola.com/sites/articles/archive/2013/05/04/iodine-deficiency-affect-childs-brain-function.aspx
1 20 percent of the iodine in your body is held in your skin (if your skin is depleted of iodine, you will not be able to sweat). 2  32 percent of your body's iodine stores are in your muscles (if muscles are depleted, pain and other fibromyalgia symptoms can develop).
http://articles.mercola.com/sites/articles/archive/2013/05/04/iodine-deficiency-affect-childs-brain-function.aspx
GOITER – Without adequate iodine, the thyroid progressively enlarges (develops a goiter) as it tries to keep up with demand for thyroid hormone production. Worldwide, iodine deficiency is the most common cause of thyroid enlargement and goiter (see Goiter brochure). Within a goiter, nodules can develop. Patients with a large goiter may experience symptoms of choking, especially when lying down, and difficulty swallowing and breathing.
http://www.thyroid.org/iodine-deficiency/
where can iodine be found
Iodine can be found in seawater, rocks and some types of soil.