What is iodine?

Also called iodide, iodine is a type of mineral that is naturally found in the earth’s soil and ocean waters. Many salt water and plant-based foods contain iodine, and this mineral is most-widely available in iodized salt.

It is important to get enough iodine in the diet. It regulates hormones, fetal development, and more.

If your iodine levels are low, your doctor might recommend supplementation. You should not take supplements without checking with your doctor first.

Read on to learn more about the uses and side effects of iodine, plus recommended daily amounts by age.

11 uses of iodine

Iodine is considered an essential mineral for our bodies. It is particularly important during pregnancy, and exposure in the womb may even help prevent certain health conditions later in life.

The following is a list of some of the most important uses and how they benefit the body.

1. Promoting thyroid health

Iodine plays a vital role in thyroid health. Your thyroid gland, which is located at the base of the front of your neck, helps regulate hormone production. These hormones control your metabolism, heart health, and more.

To make thyroid hormones, your thyroid takes up iodine in small amounts. Without iodine, thyroid hormone production can decrease. A “low” or underactive thyroid gland can lead to a condition called hypothyroidism.

Given the wide availability of iodine in western diets, thyroid health is not typically impacted by low iodine levels in the United States.

You can get enough iodine from your diet by eating dairy products, fortified foods, and salt water fish. Iodine is also available in plant foods that grow in naturally iodine-rich soil. You also can get the mineral by seasoning your food with iodized salt.

While iodine promotes overall thyroid health, too much iodine can have a negative effect on the thyroid gland. That is why you should not take iodine supplements without your doctor’s recommendation.

2. Reducing risk for some goiters

A goiter is an enlarged thyroid gland. Your thyroid may become enlarged as a result from either hypothyroidism or hyperthyroidism. Hyperthyroidism is an overactive thyroid gland.

Non-cancerous thyroid nodules (cysts) can also cause thyroid gland enlargement.

Sometimes a goiter develops as a direct response to iodine deficiency. This is the most common cause of goiter worldwide, though it’s not as common a cause in the United States and other countries with access to iodine-rich foods.

Iodine-induced goiters may be reversed by adding iodine-rich foods or supplements in the diet.

3. Managing overactive thyroid gland

Your doctor may recommend a special type of iodine called radioactive iodine to treat an overactive thyroid gland. Also called radioiodine, this medication is taken by mouth. It is used to destroy extra thyroid cells to help reduce excessive amounts of thyroid hormone.

The risk with radioactive iodine is that it can destroy too many thyroid cells. This can decrease the amount of hormone production, leading to hypothyroidism. For this reason, radioactive iodine is usually only recommended after anti-thyroid drugs have failed.

Radioactive iodine is not the same thing as iodine supplements. You should never take iodine supplements for hyperthyroidism.

4. Treating thyroid cancer

Radioiodine may also be a possible treatment option for thyroid cancer. It works in much the same way as hyperthyroid treatment.

When you take radioactive iodine orally, the medication destroys thyroid cells, including cancerous ones. It may be used as a treatment following thyroid surgery to make sure all cancerous cells have been removed from the body.

According to the American Cancer Society, radioactive iodine treatments significantly improve the chances of survival for people with thyroid cancer.

5. Neurodevelopment during pregnancy

You need more iodine in pregnancy. That is because iodine intake during pregnancy is linked to brain development in fetuses. One reviewTrusted Source found that babies whose birth mothers had an iodine deficiency during pregnancy were more likely to grow up with lower IQ’s and other intellectual delays.

The recommended daily intakeTrusted Source of iodine during pregnancy is 220 mcg. By comparison, the recommended amount in non-pregnant adults is 150 mcg a day.

If you are pregnant, ask your doctor about iodine supplementation, especially if your prenatal vitamin does not have iodine (many do not). Iodine supplements may also be necessary if you are deficient in the mineral.

You will also need to continue monitoring your iodine intake if you are breastfeeding. The recommended daily amount of iodine while nursing is 290 mcg. That is because the iodine you take up from diet and supplementation is transferred via breast milk to your nursing infant. This is a crucial brain developmental period, so infants need 110 mcg per day until they have reached 6 months of ageTrusted Source.

6. Improving cognitive function

The same neurological benefits of iodine during pregnancy may extend to healthy brain function during childhood. This also includes a reduced riskTrusted Source of intellectual disability.

It is likely your child gets all the iodine they need through their diet, but if you have any questions about their iodine intake, talk to their pediatrician.

7. Improving birth weight

As with brain development, iodine during pregnancy is associated with a healthy birth weight. One studyTrusted Source of pregnant women with goiters found that 400 mg of iodine taken daily for six to eight weeks was helpful in correcting goiters related to iodine deficiency. In turn, there was an overall improvement in birth weight in newborns.

While iodine intake can impact a baby’s birth weight and overall development, it is important to note that the above study focused on women in developing areas who were already deficient in iron.

Unless your doctor has determined you are iodine deficient, taking supplements are not likely to impact your baby’s weight at birth. In fact, taking iodine unnecessarily can cause health issues.

8. May help treat fibrocystic breast disease

It is possible that iodine supplements or medications can help treat fibrocystic breast disease. This non-cancerous condition is most common in women of reproductive age, and it can cause painful breast lumps.

Although there is some promise that iodine might help with fibrocystic breast cysts, you should not attempt self-treatment. Only take iodine for this condition if your doctor specifically recommends it. Otherwise, you could be at risk of side effects from iodine toxicity.

9. Disinfecting water

Iodine is just one method of water disinfection. This may be especially helpful if you do not have access to potable water due to traveling or effects from a natural disaster.

Two percent liquid iodine tincture may be added to water in five-drop increments per one quart of clear water. If the water is cloudy, add ten drops per quart.

Iodine tablets may also be used, but the instructions can vary by manufacturer.

Despite the role iodine can play in disinfecting drinking water, there is also some concerns that it can increase total iodine intake in humans and lead to adverse health effects. Total iodine intake should not exceed 2 mg per dayTrusted Source.

10. Protection from nuclear fallout

In the case of nuclear emergencies, the Centers for Disease Control and Prevention recommends the use of potassium iodide (KI) to protect the thyroid gland from radiation injuries. These are available in tablet and liquid formulas.

While not completely foolproof, the sooner KI is taken, the better the thyroid is thought to be protected in the event of this kind of emergency.

There are serious risks associated with KI, including gastrointestinal upset, inflammation, and allergic reaction. You are also at increased risk for thyroid disease. Your risk for complications is higher if you already have thyroid disease.

11. Treating infections

Iodine can be used topically in a liquid form to help treat and prevent infections. It works by killing bacteria in and around mild cuts and scrapes.

Topical iodine should not be used on newborn babies. It should also not be used for deep cuts, animal bites, or burns.

Follow directions on the packaging for dosage information, and do not use for more than 10 days unless directed by your doctor.

Side effects of iodine

Possible side effects from too much iodine include:

• nausea or vomiting

• diarrhea

• fever

• burning sensations in the throat and mouth

• stomach pain

In more severe cases, iodine toxicity may lead to coma.

You should not take iodine if you have a thyroid condition, unless recommended by your doctor.

Young children and the elderly are more prone to iodine side effects.

Symptoms of iodine deficiency

Iodine deficiency can only be diagnosed via urine tests.

The symptoms of low iodine levels are primarily detected through thyroid symptoms, such as:

• a visible goiter

• thyroid gland that’s painful or tender to the touch

• breathing difficulties, especially when lying down

• difficulty swallowing

• fatigue

• extreme feelings of coldness, despite normal temperatures

• hair loss

• depression

• brain fog

• unintentional weight gain

Who should take iodine?

Your doctor might recommend iodine supplements if your levels are low. The only way to know for certain is by checking your levels through a urine test. After that point, your doctor may recommend a supplement.

Iodine is available in stronger formulas through a prescription. However, these are used for serious health conditions only. For example, your doctor may recommend prescription-strength iodine if you have been exposed to radiation or have an overactive thyroid gland.

If you suspect you need iodine support, check with your doctor to see if you are a candidate.

The Role of Iodine in Cardiovascular Health

Iodine and iodine-rich foods enjoy a long history as natural therapies for hypertension and cardiovascular disease. Even when no overt symptoms are evident, hypothyroidism can contribute to heart disease and stroke, and it increases the risk of death from these conditions.

Thyroid dysfunction creates unfavorable disturbances in lipid profiles, elevating low-density lipoprotein (LDL) and total cholesterol levels and raising the risk of atherosclerosis. Hypothyroidism also weakens the heart muscle, causing it to “squeeze” less firmly with each contraction; it can cause cardiac arrhythmias as well.

These effects may not be evident at rest but become important during moderate exercise. Low thyroid function is also associated with higher waist-to-hip ratios, an obesity-related risk factor for cardiovascular disease.

Restoring normal thyroid function helps reverse multiple cardiovascular risk factors, most notably adverse lipid profiles. Yet mainstream medicine has traditionally used thyroid hormone treatment, which may be dangerous if its over-drives an already weakened heart.

Iodine therapy shows promise in safely and effectively modulating these health concerns.

Iodine Protects Against Stomach Cancer

The thyroid gland, breast tissue, and portions of the digestive tract share similarities in that all of them contain a rich concentration of iodine. Stomach lining cells in particular concentrate iodine, capitalizing on its antioxidant effects.

This has led medical researchers to investigate whether iodine deficiency plays a role in cancers of the digestive tract.

They found that people living in iodine-deficient areas of the world are not only prone to iodine-deficiency goiters, but also have higher rates of stomach cancers. Stomach cancer patients in a landlocked area of Iran were 2.5 times as likely to have severe iodine deficiency than control patients.

Gastric cancer is the most common cancer in parts of northeastern Turkey where iodine deficiency is common, and iodine levels in gastric cancer tissue were markedly lower than those in surrounding healthy tissue.

Increased iodine intake has been strongly correlated with a reduction in stomach cancer rates in recent years.

Iodine from the sea: The most effective natural form

Earth’s oceans are the main source of iodine on the planet, and nowhere is iodine as highly concentrated as in seaweed. Seaweeds such as kelp and bladderwrack can concentrate and storing iodine at high level. Scientists speculate that these primitive plants accumulate iodine to protect themselves from oxidative stress in the open ocean. Humans can reap the benefits of this natural process because the iodine in the seaweeds is in the most biologically available form, making it ideal for consumption.

In Summary

Iodine is an essential nutrient. People with access to iodized salt, seafood, and certain vegetables can get enough iodine from their diet.

Iodine is critical to healthy thyroid function. Its deficiency can cause weight gain, low energy, depression, cardiovascular disease, cognitive decline, and a variety of cancers.

Yet rates of iodine deficiency have reached epidemic levels, increasing fourfold over the past 40 years. A startling 74% of normal, “healthy” adults may no longer be consuming enough.

Recent scientific analysis reveals that many commercial table salt brands now contain inadequate amounts of iodine. Emerging evidence points to the severe impact of low iodine on a wide range of health issues, including increased risks of breast cancer and fibrocystic breast diseases.

In some cases, you may need iodine supplementation to help reduce your risk for iodine deficiency, or as a treatment for certain medical conditions, such as underactive thyroid or goiter.