Most vegetarians are likely to be Iodine deficient

Link to Iodine summary.

Iodine is very rare in vegetarian food, but recent research indicates that also the non-vegetarian diet may contain too little for good health. The extent of deficiency varies from region to region, depending on the Iodine content of the soil. The risk increases the farther away the region is from oceans. If you have used Iodized salt daily in the food you may be less deficient, but you may be far from enough according to recent research.

An notable exception is Japan, because the traditional Japanese diet, where Iodine-rich seaweed and seafood is a significant part of the traditional diet.

Selenium sufficiency very important in Iodine supplementation

It is most important that you are not deficient in Selenium when you supplement with Iodine (this will be explained further below).

Daily requirement

It is generally believed that only 150 mcg Iodine is needed per day and that Iodine is toxic at about 2000 mcg or less. But this belief was based on a research error back in the 40-ies and was never checked until recently (Abraham GE 2005). This erroneous result was widely disseminated and accepted by the medical profession. Its consequence was that, in stead of treating thyroid disorders with non-toxic Iodine, toxic and non-curative drugs have been used on millions of patients without really curing them, considering that the cause is Iodine deficiency in most cases.

Dr Guy Abraham, M.D., professor of endocrinology at UCLA, made research that indicated that the daily need is about 12500 mcg (12,5 mg) Iodine (Abraham GE 2004a and 2004b). However a recent study indicates that ther was a flaw in the method of Abraham that overestimated the need, see "How much Iodine do we really need? I will discuss the study separately in greater detail but until then, I can just indicate that the study of the Zava lab does indicate that there is a flaw in the method of Dr Abraham. For safety, until the issue is settled, i have decided to be conservative and not to specify a dose.

Abraham found after studying a number of food intake investigations that the traditional Japanese diet provides 12-13 mg Iodine daily. This intake was confirmed by the Japanese Ministry of Health and confirmed at a telephone interview (reference here). Abraham noted that this intake level coincided with the intake he found was required for maintaining Iodine sufficiency according to his research. However, the recent study of Zava lab, based on several Japanese food intake studies, arrived at about 2-3 milligrams per day.

It has been suggested that the high Iodince intake level may be the reason for the low rate of breast cancer (Stadel 1976). Also it might account for the very low rate of prostatic cancer. Abraham suggests Iodine may be one of the reasons for their superior longevity, including having the highest percentage of centenarians in Okinawa where the traditional food is used most strictly. [1].

Iodized salt contains too little according to Dr Abraham, and moreover the chloride in it inhibits the Iodine uptake so only about 10% is assimilated. Himalaya salt contains almost no Iodine (less than 1mcg/g). Oceanic sea salt contains very small amounts (about 1 mcg per gram).

Sea foods, including seaweeds are the main natural sources of Idoine.

You are likely to have a Iodine deficiency if you have been a vegetarian for some time and don't eat kelp and seaweed regularly. But even with non-vegetarian food you may become deficient in Iodine according the findings of Dr Abraham. If you have used a good amount iodized salt regularly, you may not have a significant deficiency according to conventional norms, but Abrahams experience is that the levels will not enable Iodine suffiicency.

The findings of Abraham may overestimate the need because of said error indicated by Zava lab. In any case, considering the longevity and high vitality of Japanese elders using high Iodine doses daily, it seems reasonable to conclude that it is not only safe, but conducive to good health to eat very iodine-rich food. There may also exist other important substances that go along with the Iodine and contribute to health.


[On the basis of new findings the dosage part is being rewritten]

Until the issue is further clarified I recommend as follows:

If you are a vegetarian or a non-vegetarian live far off the ocean cost, make it a habit to eat seaweed every day and as a non-vegetarian also other seafood, but be restrective with fish - there is a problematic pollution.

There are many nice, dried varieties of seaweed and kelp. Unfortunately the most Iodine rich ones have such a demand in Japan, that they are difficult to get hold of.

Together with Iodine supplementation, it is recommended always to take Selenium which plays an important role in the thyroid and other organs. The RDI is about 40 mcg and the maximum daily safe intake of Selenium is about 400 mcg (this is not the same as the daily supplementation - the contribution from food is included in this figure). Selenium is required for one of the body's most important antioxidants (glutathion peroxidase) to work and has documented anti-cancer effects, so there are good reasons to ensure that you are not deficient in it anyway. Magnesium, copper and zinc are involved in, or related to, other important antioxidants in the thyroid. For more see "Safety" below.

Selenium is deficient in the soil in certain parts of the world, including Scandinavia, parts of Central Europe including Germany, parts of America, parts of China, parts of Africa and New Zealand (this is not a complete list). In the same country there may be selenium-rich regions as well. It is good to find out what is the case in your region.

Copper may be sufficient if you have copper tubing for water. Otherwise it may sometimes be deficient in vegetarian foods. But it is toxic in higher doses so don´t take more than recommended. Ideally test the copper level. More about this later.

Magnesium is deficient in a significant part of the population. It is an important mineral involved in many key biochemical processes. It is non-toxic unless you have a severe kidney disase. [More to come]

Zinc may be deficient among vegetarians and is an important mineral, involved in about 200 enzymes. Impaired taste and smell and decreased appetite; tinnitus; disturbed sleep; dry skin and slow wound healing; hair loss; grooves, deformation and white spots of nails; weak immunity may occur at deficiency [more to come]. Zinc is found in dairy products such as milk and cheese. Pumpkin and Sesame seeds are rich in Zinc. Almonds, cashews, yeast, spinach, squash, broccoli are good vegetable sources. Legumes (especially soy), wholegrain cereals, brown rice, whole wheat bread are mentioned as sources, but their shells contains phytic acid that prevents absorbtion of Zinc and other minerals. Therefore I recommend you to avoid bran, which is a very rich source of phytic acid. Fermentation, including baking, and soaking reduce phytic acid. Baked fermented bread is prefearable. Miso, fermented soy is a good source. Zinc is water-soluble, so use the water you soaked it in. The same goes for cooking. Taking too much (over 40 mg = the official tolerable upper limit) may affects copper and iron metabolism negatively. The RDI is about 10 mg a day. [More to come]

The different minerals and trace elements work together and interact with each other in the body and therefore isolated supplementation with only a few may not give intended results. I always recommend to take a natural multi mineral & trace element preparation unless you eat organic food from a soil that is well supplied with all trace elements.

[More about minerals will be added]

It may be good to consult an experienced professional for optimal results. However quite few of them know about the recent findings of Dr Abraham regarding the Iodine requirement and his conclusion that Iodine is perfectly safe.

Iodine deficiency:

Disturbances in the thyroid gland

The research of Dr. Abraham indicates that Iodine deficiency is present in virtually all thyroid disorders and its supplementation may play a major role in curing them. This includes non-toxic and toxic goiter,  hyperthyroidism, Hashimoto's thyroiditis and other forms of hypothyroidism.

Symptoms of hypothyroidism

At early stages, the symptoms are not so specific and pronounced. Often they develop gradually. It is good to know the typical signs so that you can detect a disturbance.

[list will come soon]

NOTE [preliminary formulation]: There has been a belief that Iodine supplementation may worsen Hashimoto's autoimmune thyroiditis. However, Abrahams points out that this research is not well underpinned and a major study from China indicating this has been withdrawn (Abraham GE 2008). The same authors (Yang et al 2007) now saying "Chronic Iodine excess does not apparently increase the risk of autoimmune thyroiditis."

In any case, there is a connection between autoimmune thyroiditis and free radical production. Therefore, I recommend, especially in this condition, the use of Selenium as it is required for a key antioxidant in the thyroid. Along with it, it is good to take a powerful antioxidant supplement.

Other effects

The role of Iodine in the body goes far beyond its role in the production of thyroid hormones. Formerly it was believed that iodide concentrating cells existed only in the thyroid. Now the list has increased to include: white blood cells, salivary and tear glands, ciliary body of the eye (accomodates and nutrifies the lens), kidney cortex cells, the pancreas, the liver, the gastrointestinal channel mucosa from the ventricle throughout the colon, nose and throat, choroid plexus (produces the cerebrospinal fluid), skin, adrenal cortex (where stress hormones are produced), mammary gland, placenta, uterus, and ovary. The knowledge is still incomplete about the role of Iodine in these organs.

Below I will list effects confirmed by scientific studies or based on clinical observations. I will try go provide a rough idea about the level of evidence.


  • SCICOMF, range 1-3 = scientifically confirmed
  • SCICAS, range 1-3 = reported in scientific case studies
  • CLINOBS = Clinical observations
  • UNCLASS =unclassified

Iodine defiicency effects

  • Brain dysfunction (found in cases with moderate Iodine deficiency - of the degree possible in vegetarians) SCICOMF 3
  • Regulating moods - antidepressive effect (observed especially in hypothyroid disorder). SCICOMF 3
  • Dwarfism, psychomotor disturbance and mental retardation occurs in children of severely Iodine deficient mothers and severe Iodine deficiency in the food. SCICOMF 3
  • Antioxidant. SCICOMF 3
  • Fibrocystic breast disorder in women. SCICOMF 2
  • Preventing breast cancer. SCICOMF 1.
  • Color vision disturbances in patients with eye diseases, SCICOMF 1
  • Reducing high blood pressure. SCICOMF 1.
  • In fibromyalgia, a dramatic improvement was observed in some cases after 50 mg per day of Iodine. The addition of vitamin B3 contributed to further improvement(Abraham GE, Flechas JD 2007; Abraham GE, Flechas JD 2008). SCICAS 2
  • Improved senile macula degeneration of the eye. CLINOBS
  • Regulating blood sugar. CLINOBS
  • preventing and treating diabetes. CLINOBS
  • preventing and treating abnormal cardiac rhythms. CLINOBS
  • Improved mammary cancer. CLINOBS
  • enhanced immune function. CLINOBS
  • Eliminating systemic Candida Albicans. CLINOBS (Iodine is antifungal).
  • Eliminating chronic infections CLINOBS (iodine has powerful antibacterial, antiviral and antiparasitic effects)
  • Curing chronic gastritis through elimination of chronic Helicobacter Pylorii infection CLINOBS (may take several months to eradicate if the bacteria have penetrated inside the mucous membrane).
  • Improved restless legs. CLINOBS
  • Improved tremor. CLINOBS
  • preventing cancer in ovaries, uterus, prostate and thyroid gland. UNCLASS

The fact that some effects are not yet strongly confirmed or based only on clinical observations does not exclude that they are real. This field is new and it will take time before the more evidence has accumulated.

Fibrocystic breast disorder is prevalent in about 60% of American women and Abraham as well as Ghent (Ghent WR 1993) have reported that it can be cured with Iodine. This seems to support the opinion of Abraham that Iodine deficiency is far more prevalent than so far realized.

Iodine is a very important antioxidant

Inorganic Iodine (as in Lugol, and Iodine tincture/nascent Iodine) functions as a very important antioxidant protecting against the hydroxyl radical, which is the strongest and most dangerous free radical in the body. .

Iodine neutralizes the free radical hydrogen peroxide, preventing it from becoming a hydroxyl radical. In addition, Iodine is a specific scavenger of the hydroxyl radical.

The hydroxyl radical is a powerful neurotoxin that can damage:

  • DNA, in a way that triggers autoimmune reactions and mutations.
  • Proteins, including enzymes vital for metabolim
  • Lipids (main component of cellular walls)
  • Carbohydrates
Increased Hydroxyl radical activity has been found in several serious diseases, including Parkinsons disease, Alzheimers disease, diabetic vascular disease, inflamed rheumatic joint tissues, eye diseases (glaucoma, macular degeneration, cataract).

The body has few protective mechanisms against these very harmful hydroxyl radicals. For this reason alone it is important to ensure that one is not Iodine-deficient.

Iodine protects brain cells from free radical damage (lipid peroxidation) which is a significant health issue, because of the high level of oxygen metabolism and associated free radical generation in the brain (when we are well nutrified, antioxidative enzymes and antioxidants from the diet including Iodine take care of it, so don't worry). In brain damage due to concussion and cerebral infarction there is a greatly increased production of free radicals in the brain and it seems likely that Iodine might be valuable here, though I have not seen any studies about it (C-vitamin has been found valuable in these cases). In addition, several studies have found an increase of free radicals in psychiatric disorders including shizophrenia (Hui-chun Li, et al, 2006), where they may play an important causative role. Likewise they are increased in post-traumatic stress disorder.

Interestingly, Iodine protects against free radicals by attaching itself to the double bonds of Omega fatty acids in the cellular membranes. It is these chemically reactive double bounds that make the fatty acids vulnerable to free radicals. The brain is one of the organs with the highest density of omega fatty acids, so Iodine protection is especially essential here. (It has been maintained that high doses of Omega fatty acids may be problematic, because of their great vulnerability to free radicals and some recent research indicates an increased risk for heart complications in patients with coronary hearth disease taking Omega 3. Iodine evidently provides a good solution to this problem, provided one is well supplied.)

It has been well established that free radicals are a major factor in negative "aging". It seems reasonable to assume that the high "Iodine antioxidant" intake may be an important factor causing the longevity and vitality of people eating the traditional Japanese diet. Actually, an experimental study found that that hydroxyl radical levels decided the lifespan of banana flies (Fleming JE, 1987), and there are several studies as well confirming the role of hydroxyl radicals in shortening the life of animals (e.g. Schriner SE, et al, 2005).

Detoxification of heavy metals

Dr Abraham and colleagues have found that Iodine can help remove toxic minerals including aluminium, mercury, lead,  cadmium, fluoride and bromide from the tissues. This was indicated by considerably increased excretion of these minerals in the urine during Iodine treatment (Brownstein D, 2005) (Abraham GE, 2003). When the toxins were mobilized, fatigue and irritability sometimes temporarily appeared, which decreased at lowering the dose of Iodine.

In the case of detoxification, using high doses of Iodine, a physician, knowledgeable about Iodine detoxification should monitor the procedure.


As a last remark about Iodine I want to mention that Dr. Abraham, after extensive study of the research literature and after observing the effects of long-term treatment of high doses of Iodine on over 4000 patients, has concluded that Iodine is the safest of all minerals, and can be taken in doses thousandfold the RDI without any ill effects (Abraham GE, 2004). This, he remarks, is not a new finding, but confirms the experience of thousands of physicians using similar doses of Iodine (as Lugol's solution) for about two decades since 1920.

There are however reports that, in Selenium-deficient cases, Iodine supplementation may cause thyroid problems. Selenium is a necessary component in a powerful endogenous antioxidant (glutathione peroxidase) that plays an important role in the thyroid gland where free radicals (incl H202) are generated in the production of thyroid hormones. When Iodine is added, the production of thyroid hormones increases and then the antioxidant gluthatione peroxidase is required for effective protection although Iodine itself also has an important antioxidant effect. It is possible that Dr. Abraham's cases live in a part of the world where there is no Selenium deficiency and so there was no problem.

The bottom line is that if you are taking Iodine, it is important to supplement with Selenium unless you live in a region with Selenium-rich soils and your food comes from that region (which sometimes is not the case in these days of industrialized food production where large regions may produce only a few foods).

Where to find Lugol'solution?

Lugol is available all over the world, but in many countries the preparation is only sold at pharmacies upon physician's prescription. It is sold over the internet, but I would not recommend that unless you find a well renowned provider.

NOTE: On the internet, diluted Lugol's solution is sold by several providers, calling it Lugol. Lugol's solution contains, by definition, 5 gram elemental Iodine and 10 gram potassium Iodide on 85 ml water. Nothing else is Lugol.

Physicians will generally prescribe it for external use only. But there is no difference in the preparation whether for internal or external use.


If you take the Lugol's solution, use it only diluted, because the potassium iodide may irritate the stomach. Thas is, take it in a glass of water or juice or with food or milk.

There is a preparation, where Lugol's solution has been absorbed on unto silica in a tablet. It is called Iodoral, and does not irritate sensitive stomachs. However, this is only available presently in the US and can only be obtained on physician's prescription.

More information about Iodine

  • Iodine: Its Role In Health and Disease by Michael B. Schachter, M.D. This is a popular scientific comprehensive overview.
  • "Extrathyroidal Benefits of Iodine(pdf-file) by Professor D. Miller, M.D.". A scientific overview published in Journal of American Physicians and Surgeons Volume 11 Number 4 Winter 2006.
  • References

    • Abraham, G.E., Iodine Supplementation Markedly Increases Urinary Excretion of Fluoride and Bromide. Townsend Letter, 238:108-109, 2003.
    • Abraham GE,2004a. "The Safe and Effective Implementation of Orthoiodosupplementation In Medical Practice" The Original Internist, March 2004
    • Abraham GE, 2004b. "The concept of orthoiodosupplementation and its clinical implications." The Original Internist, 11(2):29-38, 2004
    • Abraham GE, 2005. "The Wolff-Chaikoff Effect". The Original Internist, 12(3):112-118,2005
    • Abraham GE, 2006 "The History of Iodine in Medicine Part III: Thyroid Fixation and Medical Iodophobia." The Original Internist, 13: 71-78, June 2006
    • Abraham GE, Flechas, JD. 2007. "Evidence of Defective Cellular Oxidation and Organification of Iodide in a Female with Fibromyalgia and Chronic Fatigue". The Original Internist, Vol. 14, 77-82, 2007
    • Abraham GE, Flechas, JD. 2008. "The Effect of Daily Ingestion of 100 mg Iodine Combined with High Doses of Vitamins B2 and B3 (ATP Cofactors) in Five Subjects with Fibromyalgia The Original Internist, Vol. 15, No. 1, pg. 8-15, March 2008
    • Abraham GE, 2008. "Facts about Iodine and Autoimmune Thyroiditis." The Original Internist, Vol. 15, No. 2, pg. 75-76, June 2008
    • Brownstein D, 2005, "Clinical experience with inorganic, non-radioactive Iodine/iodide." The Original Internist, 2005; 12(3):105-108.
    • Fleming JE, Shibuya1 RB, Benschand KG (1987) "Lifespan, oxygen consumption and hydroxyl radical scavenging capacity of two strains of Drosophila melanogaster". AGE 10, 86-89, 1987
    • Ghent WR, et al. (1993). "Iodine replacement in fibrocystic disease of the breast."Can J Surg, 1993; 36:453-460.
    • Stadel B., Dietary Iodine and Risk of Breast, Endometrial, and Ovarian Cancer, The Lancet, 1:890-891, 1976.
    • Hui-chun Li, et al (2006). "Imbalanced free radicals and antioxidant defense systems in schizophrenia: A comparative study". J Zhejiang Univ Sci B. 2006 December; 7(12): 981–986. 2006.

      The authors concluded: "This study showed that there are dysregulation of free radical metabolism and poor activities of the antioxidant defense systems in schizophrenic patients. Excess free radicals formation may play a critical role in the etiology of schizophrenia. Using antioxidants including Iodine, that is an important brain antioxiant, might be an effective therapeutic approach to partially alleviate or prevent the symptoms of schizophrenia."
    • Miller, D. "Extrathyroidal Benefits of Iodine" Journal of American Physicians and Surgeons Volume 11 Number 4 Winter 2006.
    • Schriner SE,1,5 Linford j,Martin GM et al ( 2005). "Extension of Murine Life Span by Overexpression of Catalase Targeted to Mitochondria".Science 24:308, pp. 1909 - 1911, 2005
    • Yang F, et al. 2007. "Chronic Iodine does not increase the incidence of hyperthyroidism: A prospective community-based epidemiological survey in China." Eur J Endocrinol, 2007; 156(4):403-8.


      1. The Okinawans have the highest percentage of centenarians in the world and the lowest death rates from cancer, heart diseases and stroke. They are notably vital at high age and have a much shorter period of decrepitude before death than commonly. See The Okinawa centenarian study.


    To the Iodine section of the homepage