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Jodbrist

Iodine is essential for the body to make thyroid hormone. Low levels of iodine may cause an underactive thyroid gland and symptoms of hypothyroidism (eg, tiredness, constipation and weight gain). Iodine deficiency in pregnant women may cause problems for the baby, including learning disability.

There has been a worldwide campaign to prevent iodine deficiency by using salt containing added iodine. However, iodine deficiency is still a widespread problem in many countries. Mild iodine deficiency may still affect some people in the UK.

Överblick

  • Iodine deficiency means your body cannot make enough thyroid hormone.

  • Livsmedel som mejeriprodukter, skaldjur, kött, vissa bröd och ägg innehåller jod.

  • Symtom kan inkludera trötthet, viktökning, förstoppning, torr hud och känsla av kyla.

  • Allvarlig brist under graviditeten kan skada barnet, vilket orsakar inlärningssvårigheter och tillväxtproblem.

  • Jodbrist diagnostiseras genom ett urinprov eller ett blodprov för sköldkörtelfunktion.

  • Du kan behandla jodbrist med jodtillskott, men för mycket kan vara skadligt.

  • Användning av jodberikat salt eller att få injektioner av jod kan hjälpa till att förebygga brist.

What is iodine deficiency?

Iodine is needed to make thyroid hormone. The body does not make iodine so your body needs foods that contain iodine. If you do not have enough iodine in your body then you cannot make enough thyroid hormone.

Which foods contain iodine?

Iodine is present in soil and seawater. If the soil has a low level of iodine then the food crops grown in that soil will also have a low iodine level. The low iodine levels in the soil will also reduce the iodine levels in farm animals grazing in that area. Foods which tend to have a higher amount of iodine include dairy products, seafood, meat, some breads and eggs.

How common is iodine deficiency?

Underactive thyroid gland due to iodine deficiency from birth (congenital hypothyroidism) is the most common preventable cause of severe inlärningssvårighet in the world. There has been a worldwide use of salt with added iodine (iodized salt) since the 1990s.

Since then the number of countries in the world with iodine deficiency has fallen. However, there are still some countries, particularly in Africa and Asia, with widespread iodine deficiency. Mild iodine deficiency may still occur in some people in the UK.

Because there are still some countries with widespread iodine deficiency, the World Health Organization is continuing a campaign to end iodine deficiency throughout the world.

What are the symptoms of iodine deficiency?

Iodine deficiency can lead to swelling of the thyroid gland (goitre) and to an underaktiv sköldkörtel (hypotyreos). In hypothyroidism, there is a reduced level of thyroid hormone (thyroxine) in the body. This can cause various symptoms, the most common being tiredness, weight gain, constipation, aches, dry skin and feeling cold.

Iodine deficiency in women who are pregnant or breast-feeding can be very harmful for the baby. Severe iodine deficiency in the mother may cause miscarriage, stillbirth and premature delivery and may cause the baby to have abnormalities when they are born (congenital abnormalities).

Children of mothers with severe iodine deficiency during pregnancy may have learning difficulties and problems with growth, hearing and speech. Even mild iodine deficiency during pregnancy may be associated with lower intelligence in children.

What tests are needed to diagnose iodine deficiency?

Iodine deficiency can be diagnosed by measuring the amount of iodine in a urine sample. However, this is usually used to monitor iodine levels in whole communities rather than for individual people. A blood test for thyroid function will also be needed for anyone who is thought to have iodine deficiency.

When to see a doctor about iodine deficiency?

If you are concerned about iodine deficiency you should discuss this with your doctor. This is particularly important if you live in a part of the world known to have low iodine levels and you are planning to become pregnant.

What is the treatment for iodine deficiency?

The treatment for iodine deficiency is to take iodine supplements. However, taking too much iodine can cause the thyroid gland to become overactive (hyperthyroidism).

People who move from a country with low iodine levels to a country with adequate iodine levels may also develop thyroid problems. Their thyroid glands will have become very good at taking up and using small amounts of iodine. Moving to an area with higher iodine levels may then cause increased thyroid activity and may even cause an overactive thyroid (iodine-induced hyperthyroidism).

How can iodine deficiency be prevented?

Elimination of iodine deficiency has been a major goal of the World Health Organization. Salt with added iodine (Iodized salt) is usually used. Injections containing iodine are occasionally used in regions of the world where widespread use of iodized salt is not possible. Adding iodine to the water supply has also been effective in some regions.

Vanliga frågor

Kan jag få tillräckligt med jod från min kost om jag bor i Storbritannien?

Även om den globala användningen av jodberikat salt har minskat jodbrist, kan mild jodbrist fortfarande förekomma hos vissa personer i Storbritannien. Livsmedel som mejeriprodukter, skaldjur, kött, vissa bröd och ägg tenderar att ha högre halter av jod.

Vilka är de långsiktiga effekterna av oupptäckt jodbrist hos barn?

Jodbrist från födseln kan vara den vanligaste förebyggbara orsaken till allvarliga inlärningssvårigheter världen över. Om mödrar har allvarlig jodbrist under graviditeten kan deras barn uppleva inlärningssvårigheter och problem med tillväxt, hörsel och tal. Även mild brist under graviditeten kan kopplas till lägre intelligens hos barn.

Finns det en risk att få i sig för mycket jod?

Ja, att ta för mycket jod kan göra att sköldkörteln blir överaktiv, ett tillstånd som kallas hypertyreos. Detta kan också hända personer som flyttar från ett område med låga jodnivåer till ett område med högre jodnivåer, eftersom deras sköldkörtlar kan överreagera på den ökade tillgången på jod.

Bör jag vara orolig för jodbrist om jag planerar en graviditet?

Det är särskilt viktigt att diskutera jodbrist med din läkare om du bor i en del av världen som är känd för att ha låga jodnivåer och du planerar att bli gravid. Jodbrist hos gravida eller ammande kvinnor kan vara mycket skadligt för barnet och kan potentiellt orsaka missfall, dödfödsel, för tidig förlossning och medfödda avvikelser.

Vidare läsning och referenser

  • Kapil U; Health consequences of iodine deficiency. Sultan Qaboos Univ Med J. 2007 Dec;7(3):267-72.
  • Chung HR; Iodine and thyroid function. Ann Pediatr Endocrinol Metab. 2014 Mar;19(1):8-12. doi: 10.6065/apem.2014.19.1.8. Epub 2014 Mar 31.
  • Iodine deficiency disorders; World Health Organization
  • Eastman CJ, Zimmermann M; The Iodine Deficiency Disorders
  • Dineva M, Fishpool H, Rayman MP, et al; Systematic review and meta-analysis of the effects of iodine supplementation on thyroid function and child neurodevelopment in mildly-to-moderately iodine-deficient pregnant women. Am J Clin Nutr. 2020 Aug 1;112(2):389-412. doi: 10.1093/ajcn/nqaa071.

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Ansvarsfriskrivning: The views expressed in the community do not represent medical advice. For any health concerns, consult your GP or healthcare provider.

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