Iodine

Minerals

18/Description

About

Iodine is a chemical element. The body needs iodine but cannot make it. The iodine needed by the body must come from the diet. As a rule, there is very little iodine in food, unless it has been added during processing. Processed food typically contains more iodine due to the addition of iodized salt. Most of the world's iodine is found in the ocean, where it is concentrated by sea life, especially seaweed.

The thyroid gland needs iodine to make hormones. If the thyroid doesn't have enough iodine to do its job, feedback systems in the body cause the thyroid to work harder. This can cause an enlarged thyroid gland (goiter), which becomes evident as a swollen neck.

Other consequences of not having enough iodine (iodine deficiency) are also serious. Iodine deficiency and the resulting low levels of thyroid hormone can cause women to stop ovulating, leading to infertility. Iodine deficiency can also lead to an autoimmune disease of the thyroid and may increase the risk of getting thyroid cancer. Some researchers think that iodine deficiency might also increase the risk of other cancers such as prostate, breast, endometrial, and ovarian cancer.

Iodine deficiency during pregnancy is serious for both the mother and the baby. It can lead to high blood pressure during pregnancy for the mother, and mental retardation for the baby. Iodine plays an important role in development of the central nervous system. In extreme cases, iodine deficiency can lead to cretinism, a disorder that involves severely stunted physical and mental growth.

Iodine deficiency is a common world health problem. The most recognized form of deficiency is goiter. Additionally, across the globe iodine deficiency is thought to be the most common preventable cause of mental retardation. Early in the twentieth century, iodine deficiency was common in the US and Canada, but the addition of iodine to salt has improved public health. The addition of iodine to salt is required in Canada. In the US, iodized salt is not required, but it is widely available. Researchers estimate that iodized salt is used regularly by about half the US population.

Iodine is used to prevent and treat iodine deficiency and its consequences, including goiter and some thyroid disorders. It is also used for treating a skin disease caused by a fungus (cutaneous sporotrichosis); treating fibrocystic breast disease and breast pain (mastalgia); weight loss; preventing breast cancer, eye disease, diabetes, and heart disease and stroke; and as an expectorant. Iodine is also used for serious bacterial diseases called anthrax and syphilis.

Iodine is also used to for radiation emergencies, to protect the thyroid gland against radioactive iodides. Potassium iodide tablets for use in a radiation emergency are available as FDA-approved products (ThyroShield, Iosat) and on the Internet as food supplements. Potassium iodide should only be used in a radiation emergency, not in advance of an emergency to prevent sickness.

Iodine is applied to the skin for skin inflammation (dermatitis) and other skin disorders such as eczema and psoriasis, to kill germs and heal wounds, to prevent soreness inside the mouth or along the digestive tract (mucositis), and treat diabetic and other external ulcers. Iodine is also applied inside the mouth to treat gum disease (periodontitis) and reduce bleeding after the removal of a tooth. Iodine can also be used as a throat rinse to reduce symptoms of pneumonia.

Iodine is used in the eyes to reduce swelling in infants and to prevent vision loss in patients with ulcers of the cornea.

Iodine is used in the vagina to prevent post-Cesarean swelling of the lining of the uterus.

Iodine is injected into a portion of the pelvis to treat a condition called chyluria.

Iodine is also used for water purification.

How it works

Iodine reduces thyroid hormone and can kill fungus, bacteria, and other microorganisms such as amoebas. A specific kind of iodine called potassium iodide is also used to prevent thyroid damage after a radioactive accident.

Effectiveness

Likely Effective
Iodine deficiency

Taking iodine supplements, including iodized salt, is effective for preventing and treating iodine deficiencies.

Radiation exposure

Taking iodine by mouth is effective for protecting against exposure to radioactive iodides in a radiation emergency. However, it should not be used for general protection against radiation.

Thyroid conditions

Taking iodine by mouth can improve thyroid storm and lumps on the thyroid called thyroid nodules.

Leg ulcers

Applying iodine in the form of cadexomer iodine or povidone-iodine to venous leg ulcers along with compression therapy seems help heal leg ulcers and reduce the chance of a future infection.

Concerns

Likely safe

Iodine is LIKELY SAFE for most people when taken by mouth at recommended amounts or when applied to the skin appropriately using approved products.Iodine can cause side effects in some people. Common side effects include nausea and stomach pain, runny nose, headache, metallic taste, and diarrhea.In sensitive people, iodine can cause side effects including swelling of the lips and face (angioedema), severe bleeding and bruising, fever, joint pain, lymph node enlargement, hives, and death. However, such sensitivity is very rare

Possibly unsafe

Large amounts or long-term use of iodine are POSSIBLY UNSAFE. Adults should avoid prolonged use of doses higher than 1100 mcg per day (the upper tolerable limit, UL) without proper medical supervision. In children, doses should not exceed 200 mcg per day for children 1 to 3 years old, 300 mcg per day for children 4 to 8 years old, 600 mcg per day for children 9 to 13 years old, and 900 mcg per day for adolescents. These are the upper tolerable limits (UL).In both children and adults, there is concern that higher intake can increase the risk of side effects such as thyroid problems. Iodine in larger amounts can cause metallic taste, soreness of teeth and gums, burning in mouth and throat, increased saliva, throat inflammation, stomach upset, diarrhea, wasting, depression, skin problems, and many other side effects.When iodine is used directly on the skin, it can cause skin irritation, stains, allergic reactions, and other side effects. Be careful not to bandage or tightly cover areas that have been treated with iodine to avoid iodine burn.

18/Warnings

Warnings

Pregnancy and breast-feeding: Iodine needs increase during pregnancy. Iodine isLIKELY SAFEwhen taken by mouth in recommended amounts or when applied to the skin appropriately using an approved product (2% solution). Iodine isPOSSIBLY UNSAFEwhen taken by mouth in high doses. Do not take more than 1100 mcg of iodine per day if you are over 18 years old; do not take more than 900 mcg of iodine per day if you are 14 to 18 years old. Higher intake has been shown to cause thyroid problems in the newborn in some cases.

Autoimmune thyroid disease: People with autoimmune thyroid disease may be especially sensitive to the harmful side effects of iodine.

A type of rash called dermatitis herpetiformis: Taking iodine can cause worsening of this rash.

Thyroid disorders, such as too little thyroid function (hypothyroidism), an enlarged thyroid gland (goiter), or a thyroid tumor: Prolonged use or high doses of iodine might make these conditions worse.

Interactions

Always consult with your doctor.
Moderate
Amiodarone (Cordarone)

Iodine can decrease thyroid function. Taking iodine along with medications for an overactive thyroid might decrease the thyroid too much. Do not take iodine supplements if you are taking medications for an overactive thyroid.Some of these medications include methenamine mandelate (Methimazole), methimazole (Tapazole), potassium iodide (Thyro-Block), and others.Amiodarone (Cordarone) contains iodine. Taking iodine supplements along with amiodarone (Cordarone) might cause too much iodine in the blood. Too much iodine in the blood can cause side effects that affect the thyroid.

Lithium

Large amounts of iodine can decrease thyroid function. Lithium can also decrease thyroid function. Taking iodine along with lithium might decrease the thyroid function too much. Do not take large amounts of iodine if you are taking lithium.

The information provided on this page is for reference purposes and is not meant to be used as a medical advice, diagnosis or treatment. Always consult with a medical professional.