Iodine is vital to the synthesis of thyroid hormones. Find out about its importance to the body, the health risks in the event of excess or deficiency, and the foods containing it.

What are the main dietary sources of iodine?

The main dietary sources of iodine are seaweed, iodised salt, marine fish, molluscs and crustaceans, as well as egg yolk and milk depending on the animal's diet.

The list of foods with a high iodine content can be found in the Ciqual table of nutritional composition of foods.


Why is iodine important to health?

Iodine is essential for the synthesis of thyroid hormones, which play a fundamental role in cell growth and maturation processes, maintenance of body temperature, regulation of energy expenditure and protein synthesis.

Iodine also plays a fundamental role in foetal brain development in the first few months of pregnancy.


What are the health risks in the event of a deficiency?

Iodine deficiency is associated with an increase in the volume of the thyroid gland and the development of goitre. Severe forms of deficiency can lead to hypothyroidism and cause fatigue, sensitivity to cold, weight gain, etc.


What are the health risks in the event of excessive intake?

Regular excessive iodine intake can lead to thyroid dysfunction.


Are some population groups more susceptible to iodine deficiency than others?

Iodine requirements vary according to age, sex and physiological condition. Iodine intake is particularly critical for the pregnant woman and her unborn child, as well as during breastfeeding.

In children, iodine deficiency can lead to mental retardation.