Iodine Supplements

Iodine supplements are important for the body because iodine is one chemical element the body cannot produce on its own. People have to take iodine supplements unless they are obtaining enough of this nutrient from their foods. However, there is very little amounts of it found in food (usually from seafood), except if foods like salt are iodized or fortified with iodine. A deficiency in iodine can lead to various health problems, including goiter (a thyroid disease), infertility, and autoimmune disease. It can also increase one’s risk of cancer in the thyroid gland. Therefore, one must learn more about taking iodine supplements and know how these may be used safely.

Effectiveness of Iodine Supplements

The effectiveness ratings for iodine are as follows:

Likely Effective For

  • Preventing/treating iodine deficiency
  • Protecting against radiation exposure
  • Improving thyroid conditions, such as hyperthyroidism and thyroid storm

Possibly Effective For

  • Painful breast disease (fibrocystic)
  • Preventing mouth sores and swelling after chemotherapy
  • Treating diabetic foot ulcers

Insufficient Evidence

  • For treating fungal skin infection and other conditions

Dosage of Iodine Supplements

1. For Radiation Emergencies

Potassium iodide or KI is usually taken just before, or just after, exposure to radiation. Dosage of iodine supplements depends on one’s age and the amount of radiation to which one is exposed (measured in centigrays or cGy). Babies, young children, adolescents, and women who are pregnant or breastfeeding are usually given KI supplements if they receive a radiation exposure of at least 5 centigrays (cGy). KI tablets may be crushed then mixed with juice or other drinks. Dosages of KI are as follows:



Newborns up to one month

16 mg

Children over one month up to 3 years


Children ages 3 -12 years


Adolescents 12 - 18 years


Large adolescents


Pregnant/breastfeeding women


Adults 18 - 40 years, exposed to


Adults exposed to ≥500 cGy

30 mg

2. Adequate Intake (AI)



Infants up to 6 months

110 mcg/day

Infants 7 - 12 months

130 mcg/day

3. Recommended Dietary Amounts (RDA)



Children ages 1- 8

90 mcg/day

Children ages 9 - 13

120 mcg/day

People above 13 years

150 mcg/day

Pregnant women

209 mcg/day

Breastfeeding mothers

290 mcg/day

4. Tolerable Upper Intake Levels (UL)

UL refers to the highest intake level not likely related to undesirable side effects.



Children ages 1-3

200 mcg/day

Children ages 4-8

300 mcg/day

Children ages 9-13

600 mcg/day

Children ages 14-18

900 mcg/day

Adults (including pregnant/breastfeeding women)

1100 mcg/day

Safety Concerns of Iodine Supplements

Although iodine is possible safe for most people when taken at recommended amounts, there are also safety concerns when using this supplement.

1. Side Effects

Oral iodine preparations, when taken at recommended doses, are usually safe. However, some people experience common side effects such as nausea, stomach pain, and headache. Others who are more sensitive to iodine may experience swelling of the face, fever, joint pains, severe bleeding and other allergic reactions such as hives and even death.

2. Precautions and Warnings

  • Pregnant and breastfeeding women who are older than 18 years old should not take >1100 mcg iodine in a day. Younger women must not take >900 mcg iodine per day. High intake may cause problems in the thyroid gland.
  • People diagnosed to have autoimmune type of thyroid disease may be more sensitive to the iodine side effects.
  • People with dermatitis herpetiformis may experience worsening of rashes.
  • Taking high doses or prolonged use of iodine may lead to worsening of these conditions: hypothyroidism (decreased thyroid function), goiter (enlarged thyroid), or thyroid tumors.

3. Interactions with Drugs

Major drug-to-drug interactions may occur when iodine is used with:

  • Medications used for overactive thyroid such as Methimazole (methenamine mandelate), Tapazole (methimazole), Thyro-Block (potassium iodide), and others.

Moderate drug-to-drug interactions may occur when iodine is used with:

  • Amiodarone (Cordarone)
  • Lithium
  • ACE inhibitors (medications used for hypertension/high blood pressure) such as lisinopril (Prinivil), enalapril (Vasotec), captopril (Capoten), and ramipril (Altace)
  • Angiotensin receptor blockers (medications also used for hypertension) such as telmisartan (Micardis), eprosartan (Teveten), losartan (Cozaar), valsartan (Diovan), irbesartan (Avapro), and candesartan (Atacand).
  • Diuretics (water pills) such as spironolactone (Aldactone), amiloride (Midamor), and triamterene (Dyrenium)