Iodine: migrant health guide

Advice and guidance on the health needs of migrant patients for healthcare practitioners.

Main messages

Iodine deficiency is rare in people born in the UK, but it is the world’s most prevalent yet preventable cause of brain damage, particularly during foetal, neonatal and infant development. It has a significant societal and socio-economic impact. Iodine deficiency also causes hypothyroidism and hyperthyroidism associated with goitre formation in both children and adults.

Iodine deficiency is on the verge of elimination globally, but populations around the globe who live in regions where the soil is deprived of iodine may still be at risk.

Consider any thyroid disorders in migrants from risk areas being the result of iodine deficiency and seek expert endocrinological advice as necessary.


Iodine is essential for:

  • the production of thyroid hormones
  • normal cognitive development

Good sources of iodine in the diet include:

  • sea fish
  • shellfish
  • milk and dairy products

Iodine can also be found in some plant foods, such as cereals and grains, and some vegetables, but levels vary depending the amount of iodine in the soil where the plants are grown.

While salt is fortified with iodine in many countries, iodised salt is not widely available in the UK.

Most people should be able to get enough iodine from a varied and balanced diet. Adults need 140 micrograms of iodine a day.

Groups at risk of iodine deficiency

Populations who live in regions of the world with iodine deficient soil are at risk of iodine deficiency unless they receive dietary or other sources of additional iodine. This includes:

  • central and mountainous areas of Europe, Asia, South America, Africa, and the Highlands of Papua New Guinea
  • floodplains, such as those of Bangladesh

The prevalence of iodine deficiency globally has been reduced by the use of iodised salt.

Anyone who avoids fish and/or dairy products (e.g. due to allergy or intolerance) may be at risk of iodine deficiency, as are vegetarians and particularly vegans as they do not eat most iodine rich foods, and therefore may need to consider a supplement containing iodine.

Effects of iodine deficiency

Iodine is an essential constituent of the hormones produced by the thyroid gland in the neck, and iodine deficiency can cause it to enlarge, a condition known as goitre.

During pregnancy, severe iodine deficiency can result in:

  • stillbirth
  • miscarriage
  • congenital abnormalities, such as cretinism

In children, iodine deficiency can impair neurological development.

In both children and adults, it can lead to:

  • hypothyroidism
  • hyperthyroidism

Excessive iodine intake

Excessive iodine intake can disrupt thyroid function, resulting in:

Responses of this type frequently occur where:

  • there is general high iodine intake
  • intervention has taken place to correct iodine deficiency


Consider the possibility that thyroid disorders in migrants from at risk regions may be due to iodine deficiency.

If you suspect iodine deficiency, seek expert endocrinological advice on:

  • the interpretation of thyroid function tests
  • other considerations
  • management of the condition and treatment
Published 31 July 2014
Last updated 20 May 2021 + show all updates
  1. Updated advice and guidance.

  2. First published.