The Complete Guide to Iodine Deficiency

The Complete Guide to Iodine Deficiency

In This Article

Iodine Deficiencies

Iodine deficiency is one of the most important and prevalent global deficiencies of the late 20th and early 21st centuries.

While great strides have been made in fighting this epidemic, there is still ample work to be done. Here are some statistics:

  • From 1971-1994, iodine intake levels in the United States decreased by 50%, according to the National Health Nutritional Examination Survey. (1)
  • Since then, iodine intake levels have stabilized, but at levels considered by experts to be on the low end of sufficient. Many groups are still considered to be at-risk, including women of child-bearing age, pregnant women and those on a voluntarily restrictive diets. (2-4)
  • According to the World Health Organization, 40% of the world’s population live in areas considered at-risk for iodine deficiency. (5,6)

Join me as I reveal why iodine deficiency is still prevalent these days, why having sufficient levels is crucial to your health, as well as the best ways to lock in your iodine stores.

Why is Iodine So Important?

While most of us are aware that iodine is a precursor to making thyroid hormones (T4 into T3), the role of iodine only begins with the thyroid.

Iodine receptors exist in each of the many trillions of cells in the body and regulate cellular function, like the movement of nutrition into the cell and the lymph drainage of toxins out of each cell.

Iodine was thought to be an antibiotic in the 1800s. Even today, before surgery, doctors rub the area to be operated on with iodine to support immunity. (8)

The Far-Reaching Benefits of Iodine

  • Supports the body’s antioxidant activity
  • Supports natural detoxification
  • Supports healthy thyroid function
  • Supports optimal hormonal function
  • Supports memory, energy, mood, and weight

Iodine Protects Against Heavy Metals, Chemicals & Toxins

One of the most important roles of iodine is to protect cells from the chemical and toxic load that has reached unprecedented levels in our environment.

Today, we dump 4 billion pounds of toxic chemicals into the American environment each year and 72 million of them are cancer-causing. (19) Fluoride is in toothpaste and some drinking water, and chlorine is in every flame retardant fabric, your shower, some drinking water, and most hot tubs and pools. Heavy metals, environmental pollutants, pesticides, off-gassing furniture, carpets, pollutants, pesticides and estrogens from plastics may be more aggressive when iodine levels are low.

Chlorine, bromine, fluorine and iodine are all halogens – this means that they attach to and compete for the same receptors in the body. (9) When iodine levels are low, the empty iodine receptors will pick up these other halogens, as well as their chemical by-products that may be even more toxic.

These toxins further compromise iodine levels, which may inhibit thyroid function, hormonal balance, and many other detox functions.

Iodine Protects Against Radiation

Since Chernobyl and, more recently, the Fukushima Daiichi nuclear disaster, radioactive iodines have been released into the global environment. These radioactive iodines compete for iodine receptors and may rob the body of functional iodine.

After Chernobyl, people for hundreds of miles around the area were given potassium iodide pills to fill their iodine receptors and protect them from environmental radiation exposure. Radiation may damage the thyroid and other iodine-sensitive tissues like the breast, prostate, brain, gastric mucosa, salivary glands, cerebrospinal fluid and ovaries.

Why We Are Iodine Deficient: Possible Factors Linked to Iodine Deficiency

  • Toxins compete with iodine receptors
  • Iodine-depleted soil
  • Chlorinated and fluoridated water
  • Lack of iodine in our diet
  • Lower salt consumption
  • Lack of dairy and wheat in our diet
  • Iodized salt loses 100% of iodine content after exposure to air for 4 weeks

When the thyroid becomes dangerously low in iodine, it may reach out, enlarge and expand in an attempt to grab onto any available iodine and cause a swollen thyroid gland, called a goiter.

Currently, the FDA has set the RDA for iodine at 150 mcg – which was clearly enough to eradicate the epidemic of goiters that plagued certain iodine-deficient areas of America in the early 1900s.

In 1924, the state of Michigan studied 66,000 school-aged children, 40% of whom had goiters. After the introduction of iodized salt into the diet, by 1928, 75% of all the children with goiters were cured. By 1950, iodine deficiency-induced goiter disease was basically eradicated. (10)

Iodized Salt: Not an Adequate Source of Iodine

While iodized salt offered enough iodine to eradicate goiter disease, iodine consumption today may not be adequate to protect thyroid function.

Today, more than 10% of the American population requires thyroid medication. 12% of the US population will develop a thyroid condition in their lifetime. One in eight women will have a thyroid condition in their lifetime, which is a five to eight times greater risk than for men. What’s more, 60% of the people who develop a thyroid condition will not even be aware that they have one. (7)

Salt is, unfortunately, not the greatest carrier of iodine. After the salt is exposed to air for 4 weeks, the salt shaker loses 100% of its iodine content. Because salt has been condemned by the medical establishment as a risk factor for high blood pressure and heart disease, salt consumption and, thus, the ingestion of iodine, is down. (11)

In addition, many health-conscious folks have stopped using refined iodized salt, as it is loaded with aluminum and is thought to leach minerals out of the body. Most people have switched to sea salt or natural mineral salts like Celtic Sea Salt, Redmond Salt or Himalayan Salt, which only contain trace amounts of iodine.

Iodine and Hormonal Balance

In Japan, the rates of breast and hormonal health are some of the greatest in the world. This may be connected to their daily iodine intake. While our RDA is just 15% of 1 milligram, reports on the iodine intake for the average Japanese person vary. Early studies suggest their daily iodine intake at 14-15 milligrams (21), while others suggest their daily intake is at 336 micrograms. (12) In one report, average habitual dosages are as much as 1500 micrograms per day and even higher for the older population who generally eat a more traditional, non-westernized diet. (20) After reviewing much of the current science available, the average intake ranges from 1-3 milligrams (1000-3000 micrograms) per day, which is the dose that studies suggest supports optimal breast health. (21)

>>> Learn more about iodine and breast health here

It is well-known that increased exposure to estrogens from plastics, a toxic environment, and synthetic Hormone Replacement Therapy can have increased health risks. Optimal iodine levels have been shown to decrease cellular responsiveness to estrogen. Iodine may also balance the concentration of estrogens in the body by building the amount of good estrogen (estriol) and decreasing the less benefical estrogens (estrone and estradiol). (13)

Symptoms of Iodine Deficiency

  • Mild fatigue
  • Blood levels of TSH greater than 2
  • Intolerance of cold
  • Cold hands and feet
  • Foggy thinking
  • Increased need for sleep
  • Dry skin
  • Thinning hair
  • Occasional Constipation

The most common symptoms of an iodine deficiency are related to hypothyroidism – low thyroid function. Unfortunately, this is not always picked up on a blood test.

Most doctors do a thyroid screening with a blood test called TSH, Thyroid Stimulating Hormone. TSH is produced at higher levels when the thyroid is not keeping up with the production of thyroid hormone. Because .465 – 4.68 uIU/mL is considered normal, most doctors won’t treat you even if you may have thyroid symptoms.

Today, there is a growing consensus that a TSH greater than 2 is an indication of low thyroid, and that a complete thyroid diagnosis includes an axillary temperature test, a comprehensive battery of blood tests including a reverse T3, as well as a thorough evaluation of symptoms, rather than just an altered TSH test. Please see a qualified doctor to order these tests.

>>> Learn more about thyroid health

If you are experiencing mild fatigue, intolerance of cold, cold hands and feet, foggy thinking, increased need for sleep, dry skin, thinning hair, or occasional constipation, you should have your thyroid levels tested.

Food Sources of Iodine: Iodine-Rich Foods (14)

  • Seaweed, 1 g
  • Cod, 3 oz
  • Yogurt, plain, 1 cup
  • Salt (iodized), not exposed to air for more than 4 weeks 1.5 g
  • Milk (cow’s), 1 cup
  • Fish sticks, 3 oz
  • Bread, enriched, 2 slices
  • Fruit cocktail in heavy syrup, canned, ½ cup
  • Shrimp, 3 oz
  • Ice cream, ½ cup
  • Tuna, canned in oil, drained, 3 oz
  • Egg, boiled, 2 large

Diets that are at risk for iodine deficiency include those void of ocean fish and sea vegetables, reduced salt (or consuming sea salt replacements instead), and vegetarian and vegan diets.

Vegetarians, who get their nutrition from iodine-depleted soils, generally have significantly low levels of iodine. In one study, iodine deficiency was noted in 25% of vegetarians and a whopping 80% of vegans. (15)

There is also a body of evidence that suggests individuals with voluntary diet restrictions in dairy, wheat, and salt are still at risk for this devastating deficiency. As more and more people are taking hard-to-digest foods like dairy and wheat out of their diet, the likelihood of iodine deficiency increases.

Ayurvedic Herbs Found to Support Thyroid

Ashwagandha – supports a healthy thyroid and is a natural adaptogen for stress.
Manjistha – supports natural lymphatic drainage from the head and neck.
Guggul – supports natural thyroid detoxification.

>>> Learn more about herbs to support thyroid health

Iodine Supports the Lymphatic System and Breast Health

According to Ayurveda and a handful of studies, iodine is a natural lymph-mover. (16) When the lymph becomes congested, certain lymph-sensitive tissues react. The breasts will swell during menses, which can be exacerbated if the lymph is congested. This can make the breasts toxic, as they are an area of lymph concentration.

Iodine deficiency may be exacerbated by lymphatic congestion, as studies suggest that the thyroid may be particularly reliant upon the lymphatic system for the adequate flow and uptake of iodine. (17,18)  As a result, those who suffer from lymphatic congestion may want to consider iodine supplementation to ensure they maintain adequate levels in the thyroid.

Symptoms of Lymphatic Congestion

  • Mild skin irritation
  • Sore joints in the morning
  • Cold hands and feet
  • Moderately swollen or sore breasts
  • Mild cellulite
  • Elevated histamine response to environmental irritants
  • Mild headaches
  • Benign cyst formation
  • Accumulated fibrous or scar tissue with age

Are You Iodine Deficient?

See a qualified medical doctor.

Step 1: Check your temperature first thing in the morning, before getting out of bed, for 5 days in a row. The average should be about 98.2 degrees. If it is less than 97 degrees, go to your doctor.

Step 2: Check your TSH (Thyroid Stimulating Hormone) levels. If they are above 2 uIU/mL, it indicates low thyroid function. This is standard on most blood tests. This should be combined with a battery of thyroid tests and, when possible, with a reverse T3 test. >>> Learn about our at-home thyroid panel test

Step 3: Evaluate symptoms mentioned above for iodine deficiency, hypothyroid and lymphatic congestion.

NOTE: If your thyroid has always tested normal, your first-morning temperature is normal and you haven’t recently begun experiencing any of the classic symptoms of hypo-thyroid, then your thyroid may be functioning well, but you may still be at risk for iodine deficiency and accumulating cellular toxicity.

Step 4: The most accurate test to determine an iodine deficiency is the 24 Hour Urinary Iodine Load Test. You take a 50 mg tablet of iodine and collect urine for 24 hours, then send it to a lab to be evaluated. If you have iodine sensitivity from eating shellfish or lobster, do not do this test.

Step 5: While the best test for iodine is the 24 Hour Urinary Load Test, an Iodine Spot Test can, in some cases, screen for a gross iodine deficiency. If there are any health concerns, I strongly suggest a consult with your doctor.

Step 6: To achieve optimal breast health and thyroid support from iodine supplementation, I suggest one capsule of Iodine HP (12mg) once every 2 weeks. One large dose of iodine mimics a large sea vegetable meal that helps to flush accumulated toxic halogens from the thyroid and out through the urine.

>>> For more information, please see more of my iodine-related articles 

Disclaimer: Due to the “high-potency” dose of iodine in Iodine HP, individuals should consult their healthcare practitioner prior to use regarding any medical conditions, including thyroid conditions, and any possible interactions with medications. High doses should be monitored by a knowledgeable healthcare professional.*

Testing is an important aspect of supra-dose iodine supplementation and should guide the use of iodine in mg doses. Experts use spot/urine testing and load testing with subsequent (24/h) urine analysis to help determine iodine need and sufficiency.*


  22. Brownstein D. Iodine, Why You Need It. Medical Alternatives Press (4th edition) 2009

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Dr. John

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