Fortified table salt is the main source of iodine. Other sources are milk and dairy products. Seaweed, fish and seafood are rich in iodine.

Iodine (symbol I) is a trace element. The thyroid gland contains the largest amount of iodine in the human body.

The thyroid gland absorbs iodine from the blood and uses it to produce thyroid hormones (triiodothyronine (T3) and thyroxine (T4)), which are released into the bloodstream as they are required.
Thyroid hormones are needed for numerous processes in the body, include building proteins, enzyme activity, myelination of nerve fibres, and cell growth. Iodine is important for normal physical growth and brain development for the foetus into infancy.