Iodine is an essential trace element that contributes to growth and metabolism. Iodine deficiency manifests itself in mental slowness, high cholesterol, depression, tiredness, weight gain and swelling of the goitre.

Iodine is found in almost every plant and animal. There are no measurements of iodine content as it varies depending on the source. In general, marine animals and plants contain the most iodine, followed by animal products. Plant products often contain only traces of iodine, but plants grown in coastal regions are richer in iodine.
Seaweed is one of the foods with the highest iodine content. Other foods containing iodine are

salt enriched with iodine, fish, jacket potatoes with skin, milk, shrimps, turkey breast and hard-boiled eggs.

Vegetarians can ensure an adequate supply of iodine by eating vegetables from coastal regions and taking iodine supplements.
The daily recommended amount of iodine is 150 micrograms. Whilst iodine deficiency is unhealthy, excessive consumption of iodine can lead to poisoning. Consuming 1mg of iodine a day can cause irritation of the mucous membranes in the mouth and throat, as well as nausea, vomiting, stomach pain and even coma.