Iodine is found in seafood and dairy products and is added to certain types of table salt. Lean fish contains about twice as much iodine as fat fish.
Why is iodine important?
Iodine is important for normal energy conversion and growth. Iodine is also important for the development of the central nervous system in children. Iodine forms part of the hormones triiodothyronine (T3) and thyroxine (T4), which contain three and four iodine atoms, respectively. The hormones are produced in the thyroid gland.
If your iodine intake is too low, the thyroid gland will try to produce enough hormones without it, and the gland will grow and you will develop goitre. If the deficiency continues, it will lead to reduced growth, low metabolism, low blood pressure and muscle weakness. Goitre is not common in the Western world, but is widespread in developing countries. Iodine deficiency is particularly serious for pregnant and breastfeeding women, as iodine is very important for brain development in foetuses and infants. Iodine deficiency is the most important cause of brain damage in children globally. This can be prevented through increased iodine intake.
The recommended intake of iodine for adults and children over the age of 10 is 150 micrograms per day. The recommended intake is slightly lower for younger children (50–120 micrograms) and slightly higher for pregnant women (175 micrograms) and breastfeeding women (200 micrograms).
Too much iodine can also lead to health problems. The intake of iodine should not exceed 600 micrograms per day.
Status in the population
The iodine status is measured in urine samples.
Iodine deficiency is uncommon in Norway, but some groups are more vulnerable than others. Food consumption surveys show that the iodine status among pregnant and breastfeeding women is lower than advisable.