Iodine is an essential mineral. Your body cannot make it, so you need to consume it in small amounts to prevent deficiency symptoms. Iodine in involved in immune system function, but is better known for its role in thyroid function. Without iodine, your body couldn't produce thyroid hormones used for the creation of protein and proper functioning of your metabolism. Although some people claim to have an iodine allergy, it isn't possible to be allergic to iodine salts or elemental iodine, which are the types of iodine found in food, according to an October 2009 article published in "Australian Prescriber."
Iodine Allergy
When people say they have an iodine allergy, it is usually an allergic reaction to the povidone-iodine found in some topical anesthetics or to iodinated radiological contrast media. This is not the same as an allergy to iodine itself. Some people also confuse a seafood allergy with iodine allergy, although seafood allergies are not related to the iodine content of seafood.
Seaweed and Iodine
Seaweed is a major source of iodine. Although the iodine content in seaweed varies -- depending on the iodine content of the water where it was harvested and the type of seaweed -- it can contain up to 4.5 mg of iodine per quarter oz. of dried seaweed. The iodine content is also relatively bioavailable to people. In fact, people who consume a lot of seaweed can exceed the tolerable upper intake for iodine of 1.1 mg per day.
Consuming Foods Containing Iodine
Because iodine can be present in small amounts in many foods, including fruits and vegetables grown in soil containing iodine, fish, eggs, dairy products and grains, it would be hard to totally avoid iodine without causing nutrient deficiencies. Because iodine allergies are not allergies to dietary iodine -- rather to certain other compounds that contain iodine -- people with iodine allergies should be able to consume seaweed and other foods that contain iodine.
Considerations
If you believe you have an iodine allergy, speak with your doctor to determine exactly what you are allergic to, so you can avoid the iodine compound that causes you adverse reactions. However, don't avoid all foods that contain iodine, unless advised to do so by your doctor, because this can cause an iodine deficiency, with symptoms including an enlarged thyroid gland, weight gain, impaired mental function, cold intolerance, constipation and fatigue.
References
- Linus Pauling Institute; Iodine; Jane Higdon, Ph.D., et al.; March 2010
- Office of Dietary Supplements: Iodine
- "Cellular and Molecular Biology"; Bioavailability of Seaweed Iodine in Human Beings; R. Aquaron, et al.; July 2002
- "Australian Prescriber"; 'Iodine Allergy' Label Is Misleading; Constance H. Katelaris, et al.; October 2009
- University of California San Francisco: Iodine Allergy and Contrast Administration
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