Iodine: Essential Trace Element for the Mind and Body

Iodine was identified as essential for humans back in the 1920s. I believe that everyone who has studied nutrition knows that a deficiency of iodine will cause an underactive thyroid. But now there is a plethora of scientific evidence showing us what else iodine does for us. And if I hadn’t seen the studies with my own eyes I would have found it hard to believe.

Every cell in our body needs iodine to function properly. The white blood cells of our immune system cannot function properly without adequate amounts of iodine. Even our sweat glands need iodine and will not function properly when we are deficient. This leads to dry skin. Neither will our salivary glands function properly. That means we would experience dry eyes and a dry mouth.

Iodine deficiency affects approximately two billion people around the world and is the number one preventable cause of intellectual disability.[1] It is crucial that both the fetus and the infant get enough in the first three years of existence or the central nervous system will not develop properly.  According to Jorge D. Flechas, MD, adding a good iodine supplement to a pregnant woman’s diet will produce a child with an IQ 20 to 30 points higher than the parents’ IQ.[2]

A good iodine supplement will contain both iodine and iodide. Like other minerals, iodine comes in several forms. Potassium Iodide and sodium iodide are the salt forms of iodine. Some organs only absorb iodine and other organs only absorb iodide. For example, only iodine will absorb in the prostate and stomach while iodide will absorb in the salivary glands, skin and the thyroid.[2]

This is why we should not take a supplement that contains only iodine or iodide but instead we should consume a supplement that contains both. One example of a supplement that contains both iodine and iodide is Lugol’s iodine.

Surveys conclude that numerous pregnant women in the United States, while not showing signs of iodine deficiency, obtain insufficient amounts of iodine.[3]  Dr. Flechas also states that a mild deficiency in the early years of life will manifest as attention deficit disorder.[2]

The World Health Organization (WHO), United Nations Children’s Fund (UNICEF), and the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) recommend an iodine intake for pregnant women of 250 mcg per day.[4] However, the average intake is much greater in in some parts of the world. For example, the average intake of iodine in Japan is considerable greater at 13.8 mg per day.

Many clinical nutritionists agree that we need considerably more iodine than the minimal amount that the WHO and other organizations are suggesting. These nutritionists also agree that the RDA was set to prevent goiter and does not take into consideration all the other bodily functions that require iodine.

The absence of iodine in a cell may allow cancer to form. The protective effect of iodine against breast cancer has been well documented in Japanese women who consume iodine-rich seaweed and have a low rate of breast cancer.[5][6] Iodine is known to induce apoptosis (programmed cell death) in breast cancer cells.[7]

A decrease in the incidence of death rate from stomach cancer after supplementation with iodine has also been reported.[8] Researchers have found a correlation between iodine deficiency and gastric cancer.[9][10]

And the list goes on; the lack of iodine can also lead to hearing loss and deafness according to Mayo Clinic.[11] Research suggests that iodine supplementation might be helpful for the treatment of fibrocystic breast disease.[12]  After a nuclear accident iodine supplementation may save your life.[13] PCOS (poly cystic ovaries) may benefit from iodine supplementation.[14]

Iodine is required for synthesizing thyroid hormones and is an integral component of them. When a person is deficient in iodine, hypothyroidism (underactive thyroid) occurs. Symptoms may include mental slowing, depression, fatigue, goiter, weight gain and low body temperature.[15] Estrogen inhibits the absorption of iodine. That is why more woman have underactive thyroids than men.

According to the National Institutes for Health (NIH) the best food sources of iodide and iodine are sea vegetables.[16] I eat sea veggies from the Atlantic Ocean such as dulse and kelp on a daily basis and also consume a number of other ocean plants such as arame, hiziki, kombu, and wakame on occasion.

I suggest that everyone find a source of iodine that feels right for them and be conscious of your intake. But since iodine is a brain stimulant, it is not advised to take it before going to sleep.

[1] McNeil, Donald G. Jr (2006-12-16). “In Raising the World’s I.Q., the Secret’s in the Salt”. New York Times. Retrieved 2008-12-04.


[3] Perrine CG, Herrick K, Serdula MK, Sullivan KM. Some subgroups of reproductive age women in the United States may be at risk for iodine deficiency. J Nutr. 2010 Aug;140(8):1489-1494.

[4] World Health Organization. United Nations Children’s Fund & International Council for the Control of Iodine Deficiency Disorders. Assessment of iodine deficiency disorders and monitoring their elimination. 3rd ed. Geneva, Switzerland: WHO, 2007.

[5] Smyth PP (July 2003). “The thyroid, iodine and breast cancer”. Breast Cancer Research: BCR (review) 5 (5): 235–8. doi:10.1186/bcr638PMC 314438PMID 12927031.

[6] Smyth PP (2003). “Role of iodine in antioxidant defence in thyroid and breast disease” .BioFactors (Oxford, England) (review) 19 (3–4): 121–30. doi:10.1002/biof.5520190304.PMID 14757962.

[7] Shrivastava, A. (2006). “Molecular Iodine Induces Caspase-independent Apoptosis in Human Breast Carcinoma Cells Involving the Mitochondria-mediated Pathway”. Journal of Biological Chemistry 281 (28): 19762–19771. doi:10.1074/jbc.M600746200ISSN 0021-9258.PMID 16679319.

[8] Golkowski, F.; Szybinski, Z.; Rachtan, J.; Sokolowski, A.; Buziak-Bereza, M.; Trofimiuk, M.; Hubalewska-Dydejczyk, A.; Przybylik-Mazurek, E.; Huszno, B. (2007). “Iodine prophylaxis—the protective factor against stomach cancer in iodine deficient areas”. Eur J Nutr. 46 (5): 251–6.doi:10.1007/s00394-007-0657-8PMID 17497074.

[9] Abnet, C. C.; Fan, J. H.; Kamangar, F; Sun, X. D.; Taylor, P. R.; Ren, J. S.; Mark, S. D.; Zhao, P. et al. (2006). “Self-reported goiter is associated with a significantly increased risk of gastric noncardia adenocarcinoma in a large population-based Chinese cohort”. International Journal of Cancer 119 (6): 1508–1510. doi:10.1002/ijc.21993PMID 16642482.

[10] Behrouzian, R.; Aghdami, N. (2004). “Urinary iodine/creatinine ratio in patients with stomach cancer in Urmia, Islamic Republic of Iran”. East Mediterr Health J. 10 (6): 921–924.PMID 16335780.


[12] Kessler JH. The effect of supraphysiologic levels of iodine on patients with cyclic mastalgia. Breast J. 2004 Jul-Aug;10(4):328-336.



[15] Felig, Philip; Frohman, Lawrence A. (2001). “Endemic Goiter”. Endocrinology & metabolism. McGraw-Hill Professional. ISBN 978-0-07-022001-0.