Posted: 04 Mar 2024 By:  Reading time: minutes remaining

How To Use Iodine For Cancer And Your Thyroid

Iodine deficiency can lead to a host of issues in the body. Learn why you need to get this mineral to balance your thyroid and other organs. Discover how to use iodine for cancer and ways to fix iodine deficiencies with your diet.


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The information is presented for educational purposes only and is not intended to diagnose, prescribe treat or cure cancer.This information is not intended as medical advice, please refer to a qualified healthcare professional.

What Is Iodine?

Iodine is an essential trace mineral not made by the body. Therefore you need to get it from food or supplements. Many saltwater and plant-based foods contain iodine. You can also find this mineral in iodized salt.

Bernard Courtois first discovered iodine in 1811 when he made gunpowder. He experimented with potassium and sodium from seaweed.


Iodine atom

Courtois observed purple vapors when he added too much sulphuric acid to the mixture. The name iodine comes from the Greek word iodes which means violet. 

Jean Francois Coindet (1774-1834) was the first to use iodine for medical use. He showed that you could reverse thyroid swelling called goiter with iodine. 

Jean-Baptiste Boussingault (1802-1887) verified the work of Coindet in 1824. Boussingault observed that goiter did not occur at many silver mining sites. His experiments showed less goiter in people who drank the water infused with iodine.

Let's look at the purpose of iodine and why you need it.

The Purpose Of Iodine

Iodine exists in each of the trillions of cells in the body. Without adequate iodine levels, life itself is not possible. Acceptable iodine levels are essential for a functional immune system.

Iodine is vital during pregnancy and may help prevent certain health conditions later in life. It is also necessary to produce thyroid hormones and other hormones in the body.

thyroid gland

The thyroid gland needs iodine to function well

Iodine plays a vital role in thyroid health. You can find your thyroid at the front and sides of your neck. Iodine enables the body to make thyroid hormones. These hormones control your metabolism, heart health, and more.

Without enough iodine, these thyroid hormones do not work. The result is an under-active(hypothyroidism) or overactive thyroid (hyperthyroidism).

Find out more about these thyroid hormones next and why you need them.

Your Thyroid Needs Iodine To Create Hormones

The thyroid-stimulating hormone (TSH), or thyrotropin, regulates the thyroid. TSH increases the uptake of iodine. It also stimulates the formation and release of T3(triiodothyronine) and T4(Thyroxine) hormones.

T4 and T3 are the most common thyroid hormones. The "4" in T4 and the "3" in T3 refer to the number of iodine atoms present.

Thyroid goiter

A goiter(thyroid swelling) can develop in the thyroid if you don't have enough iodine

In the absence of enough iodine, TSH levels remain high. The result is a goiter, an enlargement of the thyroid gland. Your body does that to trap more iodine and produce thyroid hormones. 

Thyroid hormones

  • Thyroid-stimulating hormone (TSH) 
  • Thyroid realeasing hormone(TRH)
  • Triiodothyronine(T3)
  • Thyroxine(T4)

Every cell in the body contains and utilizes iodine. The thyroid gland has a higher concentration of iodine than any other organ. You can also find iodine in: 

  • The salivary glands
  • The brain
  • Choroid plexus
  • Ovaries
  • Cerebrospinal fluid
  • Gastric mucosa
  • Breasts
  • The ciliary body of the eye

Iodine deficiency can lead to a host of conditions. Learn more about these side effects next.

Iodine Deficiency Can Lead To Serious Issues

The earth's soils contain varying amounts of iodine. Iodine is a rare element and is only the 62nd most common element on earth. You can find most iodine in seawater and rocks near the ocean. It forms when seawater evaporates.

Iodine also exists in sea organisms, such as seaweed. Seaweed is one of the most abundant sources of iodine. It concentrates a large amount of iodine from the ocean.

Crops contain adequate iodine levels if the soil has enough iodine. And iodine levels will be low in crops grown on iodine-deficient soils.

Tired woman lying in bed

Low levels of iodine can make you sick

The soil around the oceans often contains adequate amounts of iodine. And when you go inland or close to mountainous areas, iodine levels lessen. Food grown in iodine-deficient soils doesn't provide enough iodine to people there.

Thyroid hormones are essential for the normal brain development of newborn kids. Children with iodine deficiency can result in mental retardation and lowered IQ. It is the most common cause of preventable intellectual disability globally. 

Iodine deficiency also increases rates of stillbirth and deformity. During pregnancy and early infancy, iodine deficiency can cause irreversible effects.

Low levels of iodine can lead to side effects such as:

  • Goiter
  • Breathing difficulties
  • Fatigue
  • Hair loss
  • Brain fog
  • Mental retardation
  • Painful or tender thyroid
  • Difficulty swallowing
  • Extreme coldness
  • Depression
  • Unintentional weight gain
  • infertility

Because of the low rate of iodine in food, several countries added it to table salt.

Why Countries Added Iodine To Table Salt

Many countries reduced iodine deficiency by adding iodine to salt. The United States, Canada, and other countries have salt-iodization programs. The US started it in the 1920s. Today this practice is still voluntary. 

The FDA has approved using potassium iodide and cuprous iodide for salt iodization. The World Health Organization recommends potassium iodate due to its greater stability. 

Salt in hand

Many countries reduced iodine deficiency by adding iodine to salt

Iodized salt in the United States contains 45 mcg of iodine/g salt. Most salt intake in the United States comes from processed foods. Food manufacturers almost always use non-iodized salt.

Sea salt, kosher salt, and Himalayan salt are not often iodized. Product labels will say if the salt has iodine.

The thyroid also needs selenium together with iodine to work well.

The Thyroid Needs Selenium Together With Iodine

People with iodine deficiency have selenium deficiency as well. The thyroid gland needs both selenium and iodine to produce enough thyroid hormones. But when there's a deficiency in one or both, your body has low thyroid hormone levels. 

Selenium is a trace element that is essential for health. We can't make it in our bodies. Therefore we must find it in our diets or supplements. 

Selenium periodic table

The thyroid gland needs both selenium and iodine to produce enough thyroid hormones

Iodine is vital to thyroid health, and selenium is critical in recycling iodine. With low selenium levels, the thyroid will work harder to create thyroid hormones. It's essential to treat both deficits to restore thyroid health.

If you are deficient in iodine, there is a test you can do. Learn what that test is next.

How To Measure Iodine

You can measure your iodine level by looking at your urine. People excrete over 90% of dietary iodine in urine. You can check your iodine deficiency with urine tests. 

Dr. Abraham developed an iodine-loading test. It measures the amount of iodine excreted over 24 hours after taking a 50mg iodine tablet. If you're iodine insufficient, the body will hold onto more iodine. 

If you're iodine-sufficient, about 90% of the iodine/iodide excrete (45mg) in the urine. Levels below 90% excretion show an iodine-deficient state.

A man holding a sample of urine

You can measure your iodine level by looking at your urine

The National Institutes of Health (NIH) recommends this amount of iodine in micrograms (mcg) in different age groups:


Daily iodine(mcg)

Birth–6 months

110 mcg

Infants between 7–12 months

130 mcg

Children 1–8 years

90 mcg

Children 9–13 years old

120 mcg

Adults and teens, 14 and older

150 mcg

Pregnant women

220 mcg

Nursing women

290 mcg

The Recommended Dietary Allowance for iodine is 150 micrograms (mcg) daily for adults. This level includes men and women 14 or older. Pregnant and lactating women need 220 and 290 mcg daily. The tolerable upper limit is 1,100 mcg daily.

Under normal conditions, the body controls thyroid hormone concentrations via TSH. TSH secretion increases when iodine intake falls below 100 mcg/day. Hypothyroidism occurs if iodine intake falls below 10–20 mcg/day.

Iodine is not that soluble in water. Jean Lugol was a French physician. In 1829 he found that potassium iodide added to water increased the solubility of iodine. 

Dr. Lugol began using a solution termed Lugol's Iodine. It was a mixture of 5% iodine and 10% potassium iodide in water. Dr. Lugol treated many different infections with his solution and had great success. 

His recommended daily dose for various problems was two drops of Lugol's solution. This solution provided 12.5mg of iodine. Two drops of 5% Lugol's solution contain 5mg of iodine and 7.5mg of iodide.

Content Of Lugol's Iodine Solution:

  • 10% Potassium Iodide
  • 5% Iodine
  • 85% Distilled Water

High intakes of iodine can cause some of the same symptoms as iodine deficiency. Hyperthyroidism can also result from high iodine intakes. 

Iodine poisoning cases are rare and caused by overdosing by many grams. Severe poisoning symptoms include: 

  • Burning of the mouth, throat, and stomach
  • Abdominal pain
  • Vomiting
  • Weak pulse
  • Fever
  • Nausea
  • Diarrhea
  • Coma

An iodine deficiency may also increase your risk of cancer.

Can Iodine Deficiency Lead To Cancer?

Dr. David Brownstein wrote the book Iodine: Why You Need It, Why You Can't Live Without It. According to him, iodine deficiency is occurring at epidemic rates. 

Dr. Brownstein says taking thyroid hormones when deficient in iodine can worsen the thyroid. He warns that it can increase the breast, ovary, uterine, and prostate cancer risk. 

A woman with cancer sitting next to the window

In an iodine-deficient state, the thyroid, ovaries, and breasts will compete for iodine, leading to diseases

The breasts are one of the body's main storage sites for iodine. In an iodine-deficient state, the thyroid and the breasts will compete for iodine. Therefore, both will be iodine depleted. 

It can cause goiter, hypothyroidism, and breast illnesses. Ovaries contain the second highest concentration of iodine in the body. They will also deplete in an iodine-deficient state.

Another way iodine deficiency can increase cancer in women is estrogen.

The Iodine-Estrogen Cancer Connection

In women, estrogen controls female sexual development. It stimulates the growth and function of the ovaries, uterus, and breasts. The ovaries produce most estrogen in women, followed by the adrenal glands and the fat tissue.

For women, a balance of estrogens is vital for many bodily functions. Imbalanced estrogen levels can lead to weight gain, mood swings, and diabetes. It can also cause breast, ovary, and uterus cancer. Estrogen is impossible to balance when there is an iodine deficiency present.

Dr. Brownstein says that iodine deficiency changes a rat's breast tissue. Iodine deficiency in rats produces the exact precancerous changes seen in humans. 

A rat in a lab

In lab tests, rats need a healthy iodine level for estrogen to perform as it should in breasts

Dr. Bernard Eskin is one of the world's foremost researchers on iodine and the breast. He studied the effects of estrogen and iodine in rats. Eskin found that rats need a healthy iodine level for estrogen to perform as it should in breasts.

Dr. Brownstein says that researchers have demonstrated that rats given certain carcinogens will develop breast cancer. When you get enough iodine along with carcinogens, tumor formation lessens. This might show that iodine can block cancer growth in breast tissues.

Iodine deficiency has many consequences. First, it causes estrogen production to increase. Iodine deficiency also leads to an increased sensitivity of breast tissue to estrogen. These conditions can increase your disease risk, according to Dr. Brownstein. 

He also says that hypothyroidism may lead to cancer.

Does Hypothyroidism Lead To Cancer?

There is a great controversy in medicine between hypothyroidism and breast cancer. But Dr. Browstein believes there is a connection. He mentions that a goiter may lead to stomach, esophagus, ovaries, and uterus cancers.

Dr. Brownstein mentions that researchers have found that hypothyroidism is much more common in breast cancer patients. Hypothyroidism is a sign of a poor immune system. This low state can set the stage for severe illnesses such as cancer. 

Animation of breasts

Hypothyroidism is more common in breast cancer patients

Dr. Browstein warns about taking thyroid hormones. He says that women who take thyroid hormones increase breast cancer by 50%. He explains that added thyroid hormones increase the body's need for iodine. But if you don't add iodine, your body can't use thyroid hormones.

The breasts and the thyroid gland enlarge when there is an iodine deficiency. In both cases, iodine deficiency induces hyperplasia, a precancerous lesion. This condition may cause thyroid and breast diseases, including cancer. 

Dr. Browstein mentions that countries such as Japan and Iceland have higher intakes of iodine. They also have lower rates of goiter and breast cancer. 

Countries like the United States, Mexico, and Thailand have a lower intake of iodine. They also have higher incidences of both breast cancer and goiter. 

Iodine deficiency is not just due to food low in iodine. Other substances can block iodine. Are you consuming these things?

Things That Can Block Iodine Uptake

Dr. Brownstein warns about halides. Halides are elements that share a similar size and shape as iodine. This family includes fluoride, bromine, iodide, chloride, and astatide

Bromine is a toxic element that has a chemical structure like iodine. This similarity can cause bromine to bind to iodine receptors. This connection interferes with the transportation of iodine in the body. 

Bromine exists in many foods, such as bakery products and some sodas. But you can find it in many prescription items as well.

fluorite crystal

Halides such as fluoride are elements that share a similar size and shape as iodine and can interrupt iodine intake.

Fluoride can also decrease the intake of iodine. You can find fluoride in the water supply, toothpaste, and drinks. There is little evidence to support the idea that fluoride prevents cavities. 

Tobacco smoke contains a compound called thiocyanate. It can take up iodide and may be responsible for reducing levels. Hydroxypyridine metabolites, nicotine, and benzopyrene in tobacco can also impair the thyroid. 

If you think you're iodine deficient, there is some good news. You can fix this issue if you eat the following foods. Find out more next.

Good Sources Of Iodine In Your Food

There are several food sources with iodine. Some come from animal products such as cod, dairy, shrimp, tuna, and eggs. But since animal products increase cancer, you should avoid them.

But the good thing is that plants have excellent sources of iodine. The best plant-based sources come from the sea. Some examples include kelp, nori, and wakame. They are different kinds of seaweed.

Seaweed is algae that grow in the sea. There are no known toxic or poisonous forms of seaweed. Every type is edible but not tasty. 


Seaweed is a good source of iodine

Different types of seaweed have played an essential role in Japanese culture. Seaweed in Japan is often dried and packaged and available to the average household. 

Each type of seaweed has different preparation methods. Divers harvest some algae. But some facilities produce edible seaweed commercially. They can control the temperature and light.

You can buy most edible types of seaweed dried. But some can be found fresh and raw, depending on the type and season.

The best way to fix your iodine level is kelp.

How To Super Boost Your Iodine With Kelp

Kelp is any of about 30 types of brown algae that grow in colder seas. It's an important food source for many sea animals. Kelp grows in shallow saltwater near the coast. You can eat it raw, cooked, or as a powder. 

It is part of sushi, sauces, salads, seasoning, and other products. Kelp is well known as an essential element in making this basic Japanese broth, called dashi

One kelp sheet can contain up to 2,984 mcg of iodine, almost 2,000% of the recommended daily intake. Excess iodine consumption is well-tolerated by the majority of people. But too much of it can result in thyroid dysfunction.

Kelp seaweed underwater

Kelp is an excellent source of iodine

Kombu is a member of the kelp family. Most Japanese kombu comes from the waters off the coast of Hokkaido. It's also farmed in Korea, called dashima, and haidai in China.

Kelp needs nutrient-rich water with temperatures between 6 and 14 °C (43 and 57 °F). A kombu strip or kombu leaf is just a piece of kelp that has been dried flat for ease of use in the kitchen. It can be shelf-stable for years if not exposed to moisture.

Wakame is another seaweed that can improve your iodine deficiency.

Why You Should Eat Wakame

Wakame is one of the major types of edible seaweed. Japan and Korea have cultivated this seaweed for centuries. Wakame brings a unique taste and texture to soups and salads. 

It is low in calories but high in several essential nutrients. The average amount of iodine in wakame is 66 mcg per gram, or 44% of the daily recommended intake.

Wakame seaweed

Wakame is one of the major types of edible seaweed

Wakame has a deep green color. It's either dried or salted. Before using it, you need to soak it in warm water for a few minutes. Once hydrated and drained, it's added to salads and soups.

The last food I recommend to boost your iodine is nori.

Nori In Sushi Can Improve Your Iodine

Japanese nori comes from red algae. It grows in both the Northern and Southern hemispheres. It thrives best in cold nitrogen-rich water. You can use nori as part of soups, as a flavoring for other foods, or when making sushi.

Nori sheets are created by washing the nori in fresh water. You then mince it up and press it into sheets. Nori is often grown in a more controlled way using nets. 

Sushi rolls

Nori sheets used in sushi contain iodine

You then harvest it in late autumn to early winter using mechanical harvesters from a boat. It's ready when it's about 20 cm(8 inches) long. 

Nori is rich in vitamins, minerals, and dietary fibers. The iodine content in nori varies between 16–43 mcg per gram or about 11–29% of the daily value.


Iodine is an essential trace mineral not made by the body.

Acceptable iodine levels are essential for a functional immune system.

The thyroid gland has a higher concentration of iodine than any other organ.

Low levels of iodine can make you sick.

Many countries reduced iodine deficiency by adding iodine to salt.

The thyroid gland needs both selenium and iodine to produce enough thyroid hormones.

You can measure your iodine level by looking at your urine för 24 hours.

In an iodine-deficient state, the thyroid and the breasts will compete for iodine.

Iodine deficiency causes estrogen production to increase, leading to more cancer.

Hypothyroidism is more common in breast cancer patients.

Halides such as fluoride are elements that share a similar size and shape as iodine and can interrupt iodine intake.

Kelp is an excellent source of iodine.

Wakame is one of the major types of edible seaweed with iodine.

Nori sheets used in sushi contain iodine

How To Boost Iodine For Cancer

1. Consume iodine rich foods

2. Eat foods with selenium

3. Avoid iodine blockers

4. Learn more about nutrition

Action Steps

If you want to use iodine for cancer, eat foods high in this mineral. Seaweeds are the best source of iodine. Kelp or kombu has the most iodine. One kelp sheet can contain up to 2,984 mcg of iodine, almost 2,000% of the recommended daily intake.

But don't overconsume it. Excess iodine can result in thyroid dysfunction. Other foods such as wakame or nori has less iodine than kelp. Make sushi or use these seaweeds or add them to your cooking.

To balance your thyroid you also need to consume selenium. Without selenium your thyroid has a harder time producing hormones, even if  you eat enough iodine. You can find it in nuts, rice, oatmeal, and baked beans.

Also make sure to avoid stuff that block your iodine uptake. Avoid food with bromine that interferes with the transportation of iodine in the body. 

Bromine exists in many foods, such as bakery products and some sodas. You can also find it in many prescription items as well.

Eating only iodine rich foods is not enough to fight cancer. You also need to eat a healthy plant-based diet. Read our plant nutrition guide to fight cancer.

How To Fight Cancer With Plant Nutrition

iodine for cancer

Many cancer survivors have one thing in common. They started to eat plant-based to reverse their cancer.

Nutrition can be confusing. But luckily, our plant nutrition guide makes everything clear. 

The best thing? You can read it now for free without signing up with your email.


About the author 

Simon Persson

Simon Persson is a holistic cancer blogger passionate about natural health remedies. When he is not blogging, he enjoys nature, cooking, sports, and learning about the latest gadgets on the market.

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  • Do I really have to look at my urine for 24 hours???? Can I take 15 minute breaks every 2 hours or so?

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