Iodine Deficiency

Iodine deficiency occurs when your body doesn’t get enough iodine. Symptoms include an enlarged thyroid and hypothyroidism. It’s caused by a lack of iodine in your diet. Treatment involves iodine supplements and sometimes thyroid hormone supplements. You can prevent iodine deficiency by eating foods that contain iodine and using iodized salt.


What is iodine deficiency?

Iodine deficiency occurs when your thyroid gland lacks the amount of iodine it needs to function properly. Your thyroid gland is the butterfly-shaped gland located in the front of your neck. It’s part of your endocrine system. Your thyroid makes thyroid hormones. Then, your thyroid releases the hormones into your bloodstream. Your blood carries them to your body’s tissues.

Thyroid hormones help your body use energy, stay warm and keep your organs working correctly. Your unborn baby also needs thyroid hormones for proper bone and brain development during your pregnancy. Iodine deficiency during pregnancy can cause severe complications.


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What is iodine?

Iodine is a mineral of the earth. Your body needs iodine to make thyroid hormones. Your body doesn’t produce its own iodine. You must get iodine through the food you eat. You can get iodine in a few different ways:

  • Iodine is present in some foods: Iodine occurs naturally in seawater. Foods that are high in iodine include seaweed, shrimp and other seafood. Some dairy products and other foods are fortified with iodine.
  • Iodine is added to table salt: Iodine deficiency used to be common in certain areas of the United States and Canada. In 1924, the process of adding iodine to table salt was introduced. Rates of iodine deficiency dropped.
  • Iodine is available as a dietary supplement: You can get iodine through a daily multivitamin.

Who does iodine deficiency affect?

Iodine deficiency is rare in the United States. But in many other areas of the world, many people don’t get enough iodine. People who may be affected by iodine deficiency include:

  • People who don’t use iodized salt. More than 10% of the world doesn’t have access to iodized salt.
  • People who live in regions far from the sea and at higher altitudes. Their natural environments contain very little iodine.
  • People who don’t eat fish or dairy, such as vegans. Seafood and dairy products are some of the greatest sources of iodine.
  • People who are pregnant. Pregnant people need 50% more iodine than non-pregnant people to get enough iodine for their unborn baby.


What complications can occur due to iodine deficiency?

If you don’t get enough iodine, your body can’t make enough thyroid hormone. Iodine deficiency can lead to many complications, especially during pregnancy.

Iodine deficiency during pregnancy can cause:

In rare cases, iodine deficiency during pregnancy can lead to a severe form of brain damage called cretinism. Cretinism is also called congenital iodine deficiency syndrome. Babies born with this condition have severe complications including:

  • Physical and mental delays.
  • Deaf and unable to speak (deaf-mutism).
  • Severe muscle tightness (spasticity).
  • Short stature.

Symptoms and Causes

What are the signs and symptoms of iodine deficiency?

You can identify an iodine deficiency by the effects it has on your thyroid.

One of the first signs of iodine deficiency is the enlargement of your thyroid. This is a condition called goiter. Your thyroid slowly grows larger as it tries to keep up with your body’s demand for more thyroid hormone. If you have a goiter, you may experience symptoms such as:

The main symptom of iodine deficiency is hypothyroidism. Hypothyroidism occurs when your body’s iodine level decreases and your thyroid gland can’t produce thyroid hormone. This condition is also called underactive thyroid. It causes your metabolism to slow down, leading to fatigue, weight gain and the inability to tolerate cold.

Other symptoms of iodine deficiency include:


What causes iodine deficiency?

Iodine deficiency occurs when you don’t get enough iodine in your diet. While rare in the United States, iodine deficiency is a common condition in developing countries worldwide. People in areas far from water or at higher altitudes don’t get enough iodine through seafood or dairy. In addition, iodine isn’t added to table salt in some areas of the world.

Diagnosis and Tests

How is iodine deficiency diagnosed?

Your healthcare provider may be able to visually diagnose iodine deficiency if you have an enlarged thyroid gland or goiter. They may order imaging tests, such as a thyroid ultrasound or a thyroid scan to measure your thyroid gland and examine it for abnormalities.

Your healthcare provider may also order a thyroid blood test. Low levels of thyroid hormone or high levels of thyroid-stimulating hormone (TSH) can indicate iodine deficiency.

All newborn babies are checked for hypothyroidism through a blood test.

Management and Treatment

How is iodine deficiency treated?

Your healthcare provider will treat your iodine deficiency with iodine supplements. They may also recommend thyroid hormone supplements.

If your baby was born with iodine deficiency, the condition may be treated with thyroid hormone supplements. Depending on the severity of their condition, they may have to take thyroid hormones throughout their life.


How can I prevent iodine deficiency?

The best way to prevent iodine deficiency is to eat a diet that includes foods that contain iodine. Iodine can be found in:

  • Certain fish, such as cod and tuna.
  • Shrimp, seaweed and other seafood.
  • Dairy products, such as milk, yogurt and cheese.

Using iodized salt is also an important way to prevent iodine deficiency. When you add salt to your food during cooking or eating, you should use iodized salt.

Most Americans get their salt intake from processed foods such as canned goods, but processed foods rarely contain iodized salt. These foods are usually made with non-iodized salt, so they don’t help with your iodine intake.

Other salts, including sea salt, kosher salt, Himalayan salt and fleur de sel, don’t contain iodine either.

The amount of iodine you need every day depends on your age. Most adults should get 150 micrograms of iodine daily. If you’re pregnant or breastfeeding, you should take a prenatal vitamin that contains 250 micrograms of iodine daily. Not all prenatal vitamins contain iodine, so double-check the nutrients on the bottle. Ask your healthcare provider if you should take a separate iodine supplement.

Outlook / Prognosis

What can I expect if I have an iodine deficiency?

If you increase your iodine intake either through food or a supplement, the effects of iodine deficiency may decrease. If iodine deficiency isn’t caught early, severe effects can occur. If you’re pregnant, iodine deficiency can cause permanent complications in your unborn child. It’s important to get enough iodine through food or a supplement to prevent the effects from getting worse.

A note from Cleveland Clinic

Iodine is a vital nutrient that your body needs to produce thyroid hormone. Iodine is especially important for people who are pregnant or breastfeeding. Iodine deficiency is rare in the United States, but it can cause complications ranging from lower metabolism to birth defects. So it’s important to eat foods containing iodine or cooked with iodized salt. In addition, you should take a prenatal vitamin or iodine supplement if you’re pregnant.

Medically Reviewed

Last reviewed on 07/07/2022.

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