iodine

Iodine is a trace mineral used by the body to produce thyroid hormones. Iodine is not naturally synthesized by the body and must be obtained with dietary intake.

Iodine is an essential component of thyroid hormones thyroxine (T4) and triiodothyronine (T3) produced by the thyroid gland. Thyroid hormones have many important functions including the regulation of metabolic rate, temperature regulation, growth, and development, and affect virtually every body organ.

Iodine is taken as a dietary supplement by individuals who are deficient in iodine or unable to get sufficient iodine from dietary intake. Seaweed, fish and other seafood, eggs, and dairy products are good natural sources of iodine. Many foods such as bread and pasta are enriched with iodine and using iodized salt in food preparations can provide the recommended daily intake of iodine. Iodine supplements are available over the counter (OTC).

• Do not take iodine supplement if you are hypersensitive to any of its components.
• Excessive iodine may lead to reduced thyroid function (hypothyroidism) by feedback inhibition of thyroid hormone production and conversion of triiodothyronine (T3) to less active thyroxine (T4).
• Use iodine supplements with caution in patients with impaired kidney function.

Common side effects of iodine include:

• Metallic taste
• Fever
• Thyroid suppression
• Headache
• Joint pain (arthralgia)
• Diarrhea
• Acne (high dose)
• Hives (urticaria)
• Fluid in lungs (pulmonary edema)
• Swelling of tissue under the skin and mucous membranes (angioedema)
• High blood count of eosinophil immune cells (eosinophilia)

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Adult:

Recommended daily allowance (RDA)

• 150 mcg/day
• Pregnancy: 220 mcg/day
• Lactation: 290 mcg/day

Pediatric:

• Children 1-8 years: 90 mcg/day
• Children 8-13 years: 120 mcg/day
• Children 13-18 years: 150 mcg/day

• Acute iodine overdose can cause gastrointestinal upset, nausea, vomiting and diarrhea and severe symptoms include delirium, stupor and shock, but is rarely fatal. Chronic iodine toxicity can lead to thyroid inflammation (thyroiditis), hypothyroidism, hyperthyroidism, and thyroid papillary cancer.
• Iodine overdose is treated with symptomatic and supportive care, including assisted ventilation and cardiac monitoring, if necessary. Activated charcoal may be administered to eliminate any unabsorbed iodine in the gastrointestinal tract.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Iodine has no known severe interactions with other drugs.
• Serious interactions of iodine include:
  • baloxavir marboxil
• Moderate interactions of iodine include:
  • omadacycline
  • sarecycline
• Mild interactions of iodine include:
  • amiloride
  • drospirenone
  • iodine (radioactive)
  • iodoquinol
  • lithium
  • methimazole
  • potassium acid phosphate
  • potassium chloride
  • potassium citrate
  • propylthiouracil
  • spironolactone
  • triamterene

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• Iodine taken orally in recommended doses is likely safe during pregnancy. Maternal use of high doses during pregnancy and delivery may cause transient hypothyroidism in the newborn. Use with caution.
• Iodine is present in breast milk and is likely safe in recommended doses in nursing mothers. High doses may cause thyroid problems in the infant, use with caution.
• Do not use any dietary supplement including iodine without checking with your healthcare provider, if you are pregnant or breastfeeding.

• The best way to meet the daily requirement of iodine is to obtain it from dietary intake.
• Do not exceed the daily recommended dose if you take OTC iodine supplements.
• Iodine is marketed as a dietary supplement and does not require extensive pre-marketing approval from the FDA; use with caution.
• Store safely out of reach of children.
• In case of iodine overdose, seek medical help or contact Poison Control.