What is potassium iodide?

Potassium iodide (KI) is a prime source of iodine. Iodine is an essential element required by the body, meaning that humans must have a continual supply in their diet in order to maintain good health

Optimal iodine intake is necessary for normal thyroid function. The thyroid gland traps iodine from the blood and incorporates it into thyroid hormone, which is then released into circulation when needed. Thyroid hormone, or thyroxine, regulates multiple physiologic processes that include growth, development, metabolism, and reproductive function. It also aids in the conversion of food to energy and the maintenance of body temperature.

The thyroid isn’t the only organ that uses iodine. The breast, prostate gland, and skin also take up iodine for use in their intracellular activities. Researchers are working to identify how iodine is used by organs other than the thyroid.

Iodine deficiency

Without adequate iodine, hypothyroidism may develop. As the thyroid tries to keep up with the demand for thyroid hormone, it enlarges. Subsequently, a goiter may develop. Symptoms of hypothyroidism – any state in which thyroid hormone production is below normal – may include reduced mental function, fatigue, depression, excessive sleepiness, dry skin, muscle cramps, decreased concentration, increased cholesterol levels and swelling of the legs.

As the disease becomes more severe, there may be puffiness around the eyes, a slowing of the heart rate and a drop in body temperature. If left untreated, hypothyroidism can lead to an enlarged heart, worsening heart failure and an accumulation of fluid around the lungs. In its most profound form, severe hypothyroidism may lead to a life state known as myxedema coma.

Iodine deficiency in pregnant or nursing mothers can lead to significant neurocognitive deficits in their infants. Growth stunting, apathy, impaired movement, or speech and hearing problems may occur. “Cretinism” is the name of the rare but severe mental retardation that results from severe iodine deficiency during early development.

Iodine deficiency is now accepted as the most common cause of preventable brain damage in the world.

While the average American diet provides an adequate supply of iodine for most, the World Health Organization estimates that more than 30 percent of those living in developing countries may be at risk of iodine deficiency and its complications.

According to the International Council for the Control of Iodine Deficiency Disorders (INCCIDD), iodine deficiency disorders in pregnant women causes miscarriages, stillbirths, and other complications.

Several studies have demonstrated an increase in childhood survival upon correction of the iodine deficiency.

Recommended Dietary Allowance

The table below lists the recommended dietary allowances for iodine based on age and physiological state, developed by the Food and Nutrition Board of the Institute of Medicine in 2001. The column on the far right displays the amount of potassium iodide required to supply the correct level of iodine. NOTE: Figures are in MICROGRAMS, NOT MILLIGRAMS:

Age                   Iodine Potassium Iodide

Infants (0-6 months) 110 micrograms/day (AI*) 145 mcg/day

Infants (7-12 months) 130 mcg/day (AI*) 171 mcg/day

Children, 1-8 years 90 mcg/day 118 mcg/day

Children, 9-13 years 120 mcg/day 158 mcg/day

Adolescents, 14-18 years 150 mcg/day 197 mcg/day

Adults, 19 years and older 150 mcg/day 197 mcg/day

Pregnant women, all ages 220 mcg/day 289 mcg/day

Nursing women, all ages 290 mcg/day 382 mcg/day

*AI=Adequate Intake, based on observed or experimentally determined estimates of nutrient intake by a group of healthy people that are assumed to be adequate. An AI is established when an RDA cannot be determined.

Iodine excess

There are several safety concerns tied to excessive iodine intake. Symptoms of an iodine intake that is too high include a metallic taste in the mouth, soreness of the teeth and gums, burning in the mouth and throat, increased saliva, an upset stomach, diarrhea, wasting, depression, skin problems and other conditions. When iodine is used directly on the skin, it can cause irritation, stains, allergic reactions and other side effects.

More serious potential effects of excessive iodine are the precipitation of autoimmune thyroid disease and hypothyroidism. The reason for this may be that large amounts of iodine can block the thyroid’s ability to produce the thyroid hormones, thyroxine(T4) and triiodothyronine (T3). If you are unsure what your optimal daily dose of iodine is, please consult your health care provider.

Potential side effects

Iodine is safe for most people when taken by mouth at recommended amounts. However, supplements, like medicines, may occasionally cause side effects. These may include:

• Hypersensitivity reactions such as rash, swollen salivary glands, headache, wheezing or coughing, and stomach upsets are rare but may occur.

• An overactive thyroid gland (characterized by irritability, weight loss, increased appetite, intolerance to heat and increased sweating).

• An enlarged thyroid gland with or without the development of a condition in which there is thickening of the skin and body tissues, most notably the face.

People with the following conditions should not take iodine supplements without the approval of their physician:

• Hyperthyroidism

• Autoimmune thyroid disorder

• Iodine sensitivity

• Thyroid enlargement that has not been evaluated by a health care professional.

• Dermatitis herpetiformis (a skin disease)

Drug interactions

Iodine supplements can interact with the following medications: Amiodarone (a medication used to prevent abnormal heart rhythms); medications used to treat hyperthyroidism such as propylthiouracil (PTU) and methimazole; lithium; warfarin (coumarin); and others.

Consult with your health care professional before supplementing your diet with potassium iodide.

References and further reading:

International Council for the Control of Iodine Deficiency Disorders

American Thyroid Association

Linus Pauling Institute,Oregon State University Micronutrient Information Center: Iodine

Iodine: Uses and Health Benefits-MedlinePlus

Iodine deficiency, University of Michigan Health System

NOTE: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. The U.S. Food and Drug Administration (FDA) regulates herbal and other dietary supplements differently than conventional medicines. The standards for supplements are found in the Dietary Supplement Health and Education Act (DSHEA), a federal law that defines dietary supplements and sets product-label­ing standards and health claim limits. To learn more about DSHEA, visit the FDA Web site.


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