Iodine is an essential micronutrient (trace element), present in low concentrations in the soil and sea, and higher concentrations in plants and animals. Iodin assists in growth, metabolism and tissue development, and plays a role in the body’s energy production and oxygen consumption. It is most important in functioning as a component of the thyroid hormones, which regulate growth and energy expenditure, brain development and development of the baby in the womb. A major source of iodine are fish and other seafood.