Beyond its role in antisepsis and breast health, iodine is perhaps best known for its regulatory function in the thyroid gland. Educators at the Linus Pauling Institute reiterate the mineral’s essentiality to the thyroid hormones, commonly listed as T3 and T4 on a blood test. T3 is the physiologically active form, while T4 is the more abundant circulating form. In targeted tissues, T4 is converted to T3 by enzymes that depend on selenium for their activity. In this manner, the thyroid comes to control growth and development, metabolism, and reproductive function. Can you see the need for selenium? In the absence of sufficient iodine, the pituitary gland will secrete thyroid-stimulating hormone (TSH) in an attempt to set things straight by increasing iodine trapping mechanisms. If TSH levels are persistently elevated, the thyroid gland may enlarge and form what is known as a goiter.
The World Health Organization (WHO) estimates that about a third of the world’s population is deficient in iodine, a deficit that is the most common cause of preventable brain damage in the world. The Food and Nutrition Board of the Institute of Medicine declares that iodine is responsible for myelination of the developing central nervous system, and that deficiency is associated with mental retardation, and in extreme cases, cretinism. More than thirty percent of children under twelve has insufficient iodine intake. Although iodized salt was intended to prevent iodine deficiency, the modern diet has put it away in favor of salts whose iodine values are inconsistent and perhaps even absent, as might be the case with the kosher salts that took over the culinary arts. The American Journal of Hypertension and its Polish counterpart report that those adults who choose to avoid salt in any form to control their sodium-sensitive high blood pressure may be realizing small benefit in the long run unless they fortify their diets with iodine from other sources.
Just as we are barraged with loud TV commercials for products in which we have little or no interest, we are likewise assaulted with chemicals and synthetic agents about which we know nothing and whose ubiquitous presence is hidden. Manufacturers of consumer goods apparently feel the need to add things to their products for our own good when, in truth, it’s for their bottom line. Among these ruinous substances is bromine, a member of the chemical family called halides, a group that includes fluorine, chlorine, iodine and astatine, the last having no biological value whatsoever to humans. Bromine hides in a few forms—as methyl bromide and ethylene dibromide, used as fumigants. In the produce business, they relieve fresh fruits and vegetables of their B vitamins. Bromide is found in cleaners, dyes, water sanitation processes, pharmaceuticals, flame retardants in our kids’ PJs, and in our foods as brominated flour, brominated vegetable oil (BVO) and who knows what else. BVO is used to make citrus-flavored soft drinks cloudy-looking by emulsifying ingredients to keep the flavoring suspended in the liquid. Bromine, which has zero use by the body, pushes iodine out of the thyroid gland. Because it acts like iodine and chlorine, the body accepts it. Puzzlement is that bromine is listed in the Hazardous Substances Data Bank of the National Library of Medicine, yet is allowed as a food additive in the Federal Code. In one of his blog postings, Dr. David Brownstein, a celebrated holistic physician, explains that it is vital to maintain optimal iodine levels. Our constant exposure to chemicals like bromine requires daily iodine supplementation because bromine will either prevent iodine absorption or push out that which is already there. At 150 micrograms a day, the RDA for iodine is woefully inadequate to address our physiological needs. Knowing that bromine is present in some psychotropic drugs helps us to understand why some patients never get well. They are iodine depleted.
There is little doubt among researchers that iodine deficiency is epidemic. Dr. Mark Sircus acknowledges the toxicity of another halogen—fluoride. He points out that all the halogens use the same receptors in the body, and that the toxic ones will displace iodine at the first opportunity, but also that the intake of supplemental iodine can increase the excretion of the other halides, and even of heavy metals. Note that the toothpaste tube admonishes us not to let a child swallow his fluoridated dentifrice. Adults, likewise, are warned not to swallow more than used on the brush. Hailed as one of the greatest health achievements of the 20th century, fluoridation of water is now limited, being cited as harmful to the liver and kidneys.
If you or a loved one is concerned about thyroid function, know that fluoride is used in Europe to treat hyperthyroidism because it reduces thyroid activity. If you have symptoms of hypothyroid—fatigue, sensitivity to cold, constipation, dry skin, puffiness, muscle weakness, thinning hair, slowed heart rate and mental fog—look at your toothpaste, your municipal or well water supply, black tea, pesticides, Teflon, moisture barriers, some drugs, refrigerants, certain medical scanning procedures, and your dentist.
An oddity of halogens is that their clinical activity is in inverse proportion to their atomic weights. A lighter one will displace a heavier one. The opposite does not hold. Of those in the body, iodine is the heaviest. Regular use of iodine will mitigate the damage from the others. Knowing that liquid iodine preparations work more efficiently than the solid forms can help you to make the right supplement choice.
Victoria J. Drake, Ph.D.
Linus Pauling Institute Micronutrient Information Center. Mar 2010. Update
What’s happening to our iodine?
J Clin Endocrinol Metab. 1998;83(10):3398-3400.
Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002. Available at: www.nap.edu/books/0309072794/html/.
Grzesiuk W, Dabrowska J, Osikowska-Loksztejn M, Kondracka A, Kolasińska K, Bar-Andziak E.
Effectiveness of iodine prophylaxis in hypertensive patients on salt restricted diet
Pol Arch Med Wewn. 2005 Feb;113(2):147-54.
Hetzel BS, Clugston GA. Iodine. In: Shils M, Olson JA, Shike M, Ross AC, eds.
Modern Nutrition in Health and Disease.
9th ed. Baltimore: Williams & Wilkins; 1999:253-264.
Larsen PR, Davies TF, Hay ID. The thyroid gland. In: Wilson JD, Foster DW, Kronenberg HM, Larsen PR, eds. Williams Textbook of Endocrinology. 9th ed. Philadelphia: W.B. Saunders Company; 1998:389-515.
R. L. Metcalf . From the “Introduction” to Chapter 7, “Fluorine-containing insecticides”, (Handbook of Experimental Pharmacol. XX.1, pp. 355-386, Springer, Berlin-Heidelberg-New York, 1966):
Dr. Mark Sircus blogs
Santoyo-Sanchez MP, Del Carmen Silva-Lucero M, Arreola-Mendoza L, Barbier OC.
Effects of Acute Sodium Fluoride Exposure on Kidney Function, Water Homeostasis, and Renal Handling of Calcium and Inorganic Phosphate.
Biol Trace Elem Res. 2013 Feb 12. [Epub ahead of print]
Tayie FA, Jourdan K.
Hypertension, dietary salt restriction, and iodine deficiency among adults.
Am J Hypertens. 2010 Oct;23(10):1095-102.
World Health Organization. Eliminating Iodine Deficiency disorders. World Health Organization, [Web page]. 04/09/2003. http://www.who.int/nut/idd.htm. Accessed 04/11/2003.
Zhao P, Guo X, Zheng C.
Removal of elemental mercury by iodine-modified rice husk ash sorbents.
J Environ Sci (China). 2010;22(10):1629-36.
*These statements have not been evaluated by the FDA.
These products are not intended to treat, diagnose, cure, or prevent any disease.