Health and Nutrition Articles


Shop our great selection of Iodine products

Shop Now

The Most Avoidable Deficiency is On the Rise

Iodine deficiency remains low in the US; however, a condition that was once thought to have been more-or-less eradicated may once again be a cause of some concern.

Let's start at the beginning: Our bodies require iodine for the normal metabolism of cells, or, to put it simple, convert food into energy.

Your metabolism -- as well as your heart rate, blood pressure, body temperature and weight -- is regulated by hormones produced in your thyroid.

And iodine plays a critical role in the health of this butterfly-shaped gland at the base of your neck, just below your Adam's apple.

WebMd says that as well as playing a key role in your thyroid health, "iodine helps with goiters (enlargements of the thyroid gland) and low thyroid hormone levels. After exposure to radiation, iodine can provide some protection against thyroid damage."

And it suggests iodine may be able to help with foot ulcers related to diabetes and help protect against mouth irritation caused by chemotherapy.

Benefits of Iodine

The Office of Dietary Supplements says iodine has a role to play in:

  • Fetal and infant development

    Iodine is critical for babies to grow and develop properly

  • Childhood Cognitive Health

    Severe iodine deficiency during childhood affects brain and nervosa system development. And even mild iodine deficiency during childhood may lead to problems with neurological development

  • Fibrocystic breast disease

    Although not harmful, fibrocystic breast disease causes lumpy, painful breasts. It mainly affects women of reproductive age but can also occur during menopause.

  • Radiation-induced thyroid cancer

    Nuclear accidents can release radioactive iodine into the environment, increasing the risk of thyroid cancer in people who are exposed to the radioactive iodine, especially children. The FDA has approved potassium iodide as a thyroid-blocking agent to reduce the risk of thyroid cancer in radiation emergencies. adds that women with low thyroid function may not ovulate, leading to irregular cycles and infertility; pregnant women who do not take enough iodine may suffer from high blood pressure, fetal retardation or miscarriage.

Symptoms of Iodine Deficiency

If you have an iodine deficiency for some length of time, it may show itself as a goiter, the classic symptom of which is swelling around your thyroid gland that results in a visible lump in your throat.

This condition may affect your ability to swallow and your glands ability to produce much needed hormones.

If your body does not produce sufficient hormones, you may develop hypothyroidism, which can actually occur with or without a goiter.

Signs of hypothyroidism may be subtle at first and early symptoms may include

  • Fatigue
  • Depression
  • Weight gain
  • Mental impairment
  • Decreased concentration
  • Constipation
  • Dry skin
  • Severe indications of this condition include
  • Puffy eyes
  • Decreased heart rate
  • Coma

Iodine Deficiency Returns

However, iodine deficiency is generally recognized as the most commonly avoidable cause of mental retardation and the most common cause of goiter and primary hypothyroidism.

And fortunately, according to the the Mayo Clinic, "iodine deficiency in the United States is rare because iodine is added to table salt."

Indeed, for many years iodine has been added to table salt and, in generous quantities, to the bread we eat.

This put an end to what had been a common deficiency in the early 20th century in the US and Canada. Iodine has to be added to salt in Canada. That is not the case in the US, but iodized salt is widely available. It is estimated that iodized salt is used regularly by about half the US population.

And while there was a period from the 1970s to the mid-1990s when iodine levels dropped by almost 50% in the US, according to the National Health and Nutrition Survey (NHANES), that situation has now stabilized.

However, there is no room for complacency. And various groups, most notably women of reproductive age, may suffer from iodine deficiency.

For example, the Office of Dietary Supplements says pregnant women who do not eat dairy products may be especially at risk of iodine insufficiency.

But the issue is much bigger than that.

According to Dr Mercola: More than 11% of all Americans, and more than 15% of American women of child-bearing age, presently have... moderate to severe iodine deficiency. An additional 36% of reproductive-aged women in the US are considered mildly iodine deficient."

And Dr David Brownstein, author of Iodine: Why You Need It Why You Can't Live Without It, says his Michigan practice has tested more than 6,000 patients and found iodine deficiency occurring at epidemic rates.

What's Behind this Resurgence of Iodine Deficiency

Most of us have heard how low-sodium diets can help reduce blood pressure. Food manufacturers and fast-food outlets are even reducing the amount of salt in their foods, much of which is not iodine enriched, anyway.

However, reducing your salt intake may increase your risk of iodine deficiency, especially if iodized salt is your main source.

But there are other threats, too.

Much of our food is now grown on iodine deficient soil, especially if you live in the states bordering Canada. However, soils in California and Texas are also low in iodine.

And the dairy industry no longer adds iodine to animal feedstuff; many of us are cutting back on eggs for our cholesterol levels; and we are developing a taste for sea salt, which has no added iodine.

But there's more. Commercial bakers are increasingly replacing iodine used in flour processing with bromide (potassium bromate), which helps makes flour doughier, rise higher, and gives the loaf a better appearance. But bromide not only replaces iodine but also blocks the activity of iodine. That's also true for chlorine and fluoride, both of which are common in drinking water.

Healthy Levels of Iodine

There is also some doubt about the recommended levels of iodine in the US.

The American Thyroid Association recommends that pregnant and breastfeeding women take prenatal vitamin/mineral supplements containing iodine (150 mcg/day).

And the Office of Dietary Supplements (ODS) recommends the following levels:

Recommended Iodine Levels
Life Satge Recommended Amount
Birth to 6 months 110mcg
Infants 7-12 months 130mcg
Children 1-8 years 90mcg
Children 9-13 years 120mcg
Teens 14-18 years 150mcg
Adults 150mcg
Pregnant teens and women 220mcg
Breastfeeding teens and women 290mcg

However, there is an argument that the low cancer rates in Japan, the lowest in the world, are a result of their substantially higher levels of iodine, thanks to its antioxidant and anti-proliferative properties.

Natural Healthy Concepts founder Theresa Groskopp says: "There is growing evidence that Americans would have better health and a lower incidence of hypothyroidism, cancer, and fibrocystic disease of the breast if they consumed more iodine."

She says: "People in the US consume an average of 240 micrograms of iodine a day. In contrast, people in Japan consume more than 12 milligrams of iodine a day, 50 times more, mostly in the form of sea vegetation."

Groskopp says: "Today, 1 in 7 American women, or almost 15%, will develop breast cancer during their lifetime. Thirty years ago, when iodine consumption was twice as high as it is now... 1 in 20 women developed breast cancer".

Foods High in Iodine

As mentioned earlier, table salt has long been the main food source of iodine. However, there are other sources.

Seafood, for example, including cod, sea bass, haddock, and perch, are good sources. And for the vegetarians out there, kelp is also a rich source of iodine.

Dairy foods, soy milk and sauce, and egg are also good

The ODS provides a table of selected food sources:

Selected Food Sources of Iodine
Food Approximate Micrograms (mcg) per serving % Daily Value
Seaweed, whole or sheet, 1 g 16 to 2,984 11% to 1,989%
Cod, baked, 3 ounces 99 66%
Yogurt, plain, low-fat, 1 cup 75 50%
Iodized salt, 1.5 g (approx. 1/4 teaspoon) 71 47%
Milk, reduced fat, 1 cup 56 37%
Fish sticks, 3 ounces 54 36%
Bread, white, enriched, 2 slices 45 30%
Fruit cocktail in heavy syrup, canned, 1/2 cup 42 28%
Shrimp, 3 ounces 35 23%
Ice cream, chocolate, 1/2 cup 30 20%
Macaroni, enriched, boiled, 1 cup 27 18%
Egg, 1 large 24 16%
Tuna, canned in oil, drained, 3 ounces 17 11%
Corn, cream style, canned, 1/2 cup 14 9%
Prunes, dried, 5 prunes 13 9%
Cheese, cheddar, 1 ounce 12 8
Raisin bran cereal, 1 cup 11 7%
Lima beans, mature, boiled, 1/2 cup 8 5%
Apple juice, 1 cup 7 5%
Green peas, frozen, boiled, 1/2 cup 3 2%
Banana, 1 medium 3 2%

Iodine Side Effects

Taking iodine supplements over an extended period of time may lead to hypothyroidism by blocking your body from producing thyroid hormones.

Iodine supplements may also cause:

  • Upset stomach
  • Stomach pain
  • Headache
  • Runny nose
  • Diarrhea
  • Metallic taste in the mouth

Find Out if You Have Iodine Deficiency

If you would like to be tested for iodine deficiency, you can ask your healthcare provider about the urine iodine challenge test.

Although there is a very rough simple DIY test: Simply, touch with slightly wet fingers and if you leave a yellowish stain, iodine is coming out of your skin and you are getting enough. This is not a full proof test however.

Shop our great selection of Iodine products

Shop Now


Quick Facts

  • Your body requires iodine to convert food into energy
  • Iodine is critical for babies to grow and develop properly
  • Reducing your salt intake may increase your risk of iodine deficiency, especially if iodized salt is your main source
  • Even mild iodine deficiency during childhood may lead to problems with neurological development
  • More than 11% of all Americans and over 15% of women of child-bearing age have moderate to severe iodine deficiency
  • Iodine deficiency is generally recognized as the most commonly avoidable cause of mental retardation
  • Much of our food is now grown on iodine deficient soil
  • A common symptom of iodine is the formation of a goiter, which develops when the butterfly-shaped thyroid gland at the base of your neck swells
  • Seafood, including cod, sea bass, haddock, and perch, kelp, dairy foods, and eggs are good sources of iodine