Iodine is an essential trace element required for the synthesis of thyroid hormones.
Iodine is a minor non-metallic mineral, qualified in nutrition as a trace element due to its low quantitative importance, although it is vital for the body.
Iodine is absorbed from the blood by the thyroid gland. Thyroid hormones play an intrinsic yet basic role in regulating basal metabolic rate. A total deficiency can reduce basal metabolic rate by up to 50%. Excessive production of thyroid hormones can increase metabolic rate by 100%.
Good sources of iodine include kelp, certain seafood and plants grown in iodine-rich soils. Iodised salt is fortified with iodine.