What is iodine?

Iodine is an essential mineral, which means your body needs it to function properly. You cannot produce it yourself, it must be ingested through the diet or as a supplement.

It is a trace element, or a relatively small part of body tissue. This means your body only needs a small amount.

Iodine is present in food, but the amount is difficult to determine. Iodized salt is the main source of this mineral in the United States. Most people need to use iodine-rich salt on a regular basis in order to get enough iodine in their diet.

This article discusses the uses of iodine and the recommended amount of iodine. It also covers what happens when you get too little or too much iodine.

What is iodine good for?

Iodine is an important component of thyroid hormones. These hormones help your body regulate weight, internal temperature, and energy levels. They also play a role in skin, hair and nail growth.

In addition to thyroid hormone production, iodine may play a role in bodily functions, but the evidence is not entirely clear.

Your thyroid produces the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Both of these contain iodide (a form of iodine).

Iodine is ingested by mouth and is rapidly absorbed in the stomach and small intestine. It goes through the blood. From there, iodine receptors (located in the thyroid) bind to it and absorb it.

T4 hormone contains four iodine molecules, while T3 thyroid hormone contains three iodine molecules. After the thyroid produces T4, it releases it into the blood. T4 is then converted to T3, which interacts with most cells in the body.

Active T3 thyroid hormone works in nearly every cell and organ of the body by regulating metabolism, energy use, growth and repair.

iodine deficiency

Iodine deficiency can cause problems with thyroid hormone production. This can lead to symptoms of thyroid disease.

If your iodine levels are low, symptoms of thyroid dysfunction may appear within a few weeks. They include various conditions:

Hypothyroidism (underactive thyroid)

An iodine deficiency can prevent your body from producing enough thyroid hormones, leading to hypothyroidism.

This can cause a variety of symptoms, including:

  • weight gain
  • energy reduction
  • sleepy
  • inability to concentrate
  • frustrated
  • constipate
  • always feel cold
  • irregular menstruation
  • blood sugar problems

hypothyroidism in children

Dietary iodine deficiency is one of the main preventable causes of cognitive (intellectual) and developmental impairments in many parts of the world.

Children with iodine deficiency may experience the same effects and other symptoms as adults. Effects can be subtle and gradual and include slower physical development, emotional problems, difficulty concentrating, and learning difficulties.


When you have hypothyroidism, your body doesn’t make enough thyroid hormones. It can lead to weight gain, decreased energy, poor concentration, irregular periods, and more. In addition to slow growth, emotional problems, and learning difficulties, children may experience these symptoms.


Iodine deficiency can cause thyroid hormone levels to decrease. In response, your pituitary gland produces excess thyroid-stimulating hormone (TSH) to compensate for these low levels.

TSH normally stimulates the thyroid to produce and release T4 and T3. However, too much TSH can overstimulate the thyroid.

The thyroid then gets bigger, but still cannot function fully without enough iodine. This change is described as a goiter.

congenital hypothyroidism

Infant iodine deficiency is detected with a newborn screening test. This condition can cause feeding difficulties, muscle tension, or heart problems in the baby. Sometimes, it may not cause any symptoms at all.

Although there are other causes, newborns born to mothers with low iodine intake during pregnancy may develop congenital hypothyroidism.

This improves if the baby gets enough iodine in the diet after birth. If they don’t, they risk learning deficits and limited physical development due to an underactive thyroid.

It has been suggested that iodine deficiency may also be associated with breast disease, stomach problems and bone problems, but these concerns have not been proven.

Thyroid hormone

In some cases, your iodine may not work as it should, if Thyroid hormone Interferes with the absorption of iodine by the thyroid gland.

A goiter is food and other substances that compete with the thyroid for iodine absorption. This prevents the normal production of thyroid hormones.

Some goitrogens include broccoli, cabbage, cauliflower, kale, and strawberries. If your thyroid function and iodine intake are normal, there is no need to worry about these foods causing iodine deficiency.

Goiter and your thyroid health

side effect

In general, moderate intake of iodine from iodized salt or foods in the diet is not a problem. Excess iodine is easily excreted through urine.

However, you can consume more iodine than your body can handle by using supplements that contain high doses of iodine. Chronic iodine excess is associated with goiter, hyperthyroidism, thyroiditis, and thyroid cancer.

In rare cases, iodine poisoning can result from ingesting large amounts of iodine supplements.

Children who eat an entire bottle of vitamin pills or adults with kidney failure who use supplements may not be able to properly eliminate excess iodine. Symptoms may include upset stomach, vomiting and diarrhea.

Iodine Allergy and Sensitivity

Hypersensitivity and sensitivity to iodine has been reported. There are three types of iodine reactions:

  • Skin Sensitivity: Topical iodine (applied directly to the skin) can cause skin redness and pain. This reaction is usually self-limiting and usually resolves on its own within a few hours.
  • Allergies: Allergy to ingested iodine remains a controversial topic. In the past, seafood allergies have been blamed on iodine. Medical experts now believe that seafood allergies are caused by another component of seafood, not iodine.
  • Contrast media (injected) iodine: Contrast media injected for imaging studies often contain iodine. Often, people have allergic reactions to injected contrast media. Whether iodine plays a role in this reaction is unclear. Medical experts currently believe that iodine is not the cause of allergic reactions to contrast media, but the problem remains.


Allergic reactions have been reported when iodine is ingested in seafood or injected for imaging studies. However, some medical experts question whether these allergies are caused by iodine or other ingredients.

Dosage and Preparation

Iodine is added to table salt and is labeled “iodized salt.”

All children and adults need regular iodine intake due to the constant production of thyroid hormones. Pregnant women need larger amounts to support their developing babies.

The Institute of Medicine recommends the amount of iodine a person should consume each day.

Recommended iodine intake

  • 90-130 mcg per day for children (depending on age)
  • 150 mcg per day for adults (and teens 14-18)
  • 220 micrograms per day for pregnant women

measure iodine levels

Iodine levels cannot be measured in blood, but they can be measured in urine. Urine measurements of iodine are considered a reflection of iodine intake.

Normal urinary iodine concentrations range from 100 to 200 micrograms per liter. Values ​​below 20 micrograms per liter indicate insufficient iodine intake.

Common sources of iodine include:

  • Salt: Iodized salt contains an average of 45 micrograms of iodine per gram. This concentration may vary by manufacturer. For exact amounts, check the nutritional information on the label.
  • Food: Iodine is a component of seafood, milk, vegetables and fruits. Fish and seaweed are the foods with the highest iodine content. One serving of fish contains about 90 micrograms of iodine, and one serving of seaweed has about 200 micrograms of iodine.
  • Supplements: Vitamins and supplements vary in their iodine content. You can find the specific iodine content on the label. Consult your healthcare provider before taking supplements.


Iodine levels in urine can be measured. Normal levels range from 100 to 200 micrograms per liter. Common sources of iodine are salt, supplements, and foods such as fish and seaweed.

medical use

Radioactive iodine is used as a drug to treat conditions such as thyroid cancer or goiter. It is often used to destroy overactive thyroid tissue or thyroid cancer.

This treatment is a prescription drug and requires a special low-iodine diet for several weeks before starting treatment. Radioactive iodine can be harmful to others, so precautions need to be taken to protect others. This includes covering the neck during treatment.

Over-the-counter and prescription forms of iodine solutions are commonly used to prevent infection. Often added to topical antiseptics, this mineral is thought to destroy infectious microbes with minimal risk of side effects.

Iodine is also used in preoperative care. It is a component of povidone-iodine, one of the preparations used in surgical procedures to prevent infection.

In rare cases, a nuclear emergency associated with a radioactive iodine leak can pose a serious health threat to the public. In these cases, potassium iodide can be used to prevent thyroid damage.

iodine supplement

Salt is rich in iodine, which is naturally present in some foods. Therefore, iodine supplementation is not recommended unless your healthcare provider has diagnosed an iodine deficiency. In fact, a low-iodine diet is often recommended for thyroid disease.

If you have to follow a very low-salt diet due to other health problems, you may need iodine supplementation.

Do not use iodine supplements unless you have been diagnosed with iodine deficiency. If you need an iodine supplement, your healthcare provider will give you a prescription. You may be able to use over-the-counter supplements. If so, verify that the dosage is exactly as prescribed by your healthcare provider.


Iodine is a mineral that the body needs to produce thyroid hormones. These hormones play an important role in regulating weight, maintaining energy, and growing hair, skin, and nails.

Iodine deficiency can lead to hypothyroidism, which is the inability of the thyroid gland to produce enough thyroid hormones.

Common sources of iodine include salt, supplements, and foods such as vegetables and seafood. Consult your doctor before taking any supplements.

VigorTip words

Iodine deficiency is rare in countries where iodized salt is regularly used. If you have thyroid problems, you may have been told to stay on a low-iodine diet or supplemented with iodine.

If you have been iodine deficient in the past, consult your doctor to monitor your thyroid hormone levels regularly. Regular check-ups are the best way to know if you are getting enough iodine.

Frequently Asked Questions

  • What is an iodine solution?

    Iodine solution is a mixture of iodine and water. Iodine supplements can be high in minerals, so when iodine supplements need to be consumed, a solution is created to lessen their effects. The number of correct solutions to take should be discussed with the healthcare provider.

  • Can iodine deficiency cause low energy levels?

    Iodine deficiency can affect your thyroid hormone levels, leading to low energy levels. However, iodine deficiency does not affect energy levels independently of thyroid hormones. If you have low energy or other symptoms of thyroid disease, you can check your thyroid levels.

  • Can eating salty food cause iodine poisoning?

    Eating salty foods should not cause iodine poisoning. The body automatically removes excess iodine during urination. However, consuming too much iodine supplements is not safe and can cause stomach upset, diarrhea, and vomiting.

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