Indications
Iodide (usually as potassium iodide) is a source of iodine, a mineral the body needs to make thyroid hormones. It is included in multivitamin and mineral supplements to help prevent iodine deficiency, which can cause goitre (swelling of the thyroid), tiredness and weight gain, and in pregnancy can harm the baby’s brain development. Higher-dose iodide products are used in special situations, such as protecting the thyroid after a radiation emergency or before thyroid surgery, only on medical advice.
How It Works
The thyroid gland takes up iodide from the blood and uses it to build the hormones thyroxine (T4) and triiodothyronine (T3), which control the body’s metabolism, energy use and growth. Getting enough iodide keeps hormone production normal.
Dosage and Administration
The recommended daily iodine intake for adults is about 150 mcg, and about 250 mcg during pregnancy and breastfeeding. Supplements should be taken as directed on the label, usually once daily with food. Using iodised salt helps meet daily needs. High-dose iodide for medical uses is taken only as prescribed.
Interactions
Iodide can change thyroid test results and the effect of thyroid medicines such as Levothyroxine, Carbimazole and Methimazole. Taking it with Lithium may increase the risk of an underactive thyroid. Combining it with potassium-sparing diuretics (such as Spironolactone), ACE inhibitors or ARBs may raise potassium levels when potassium iodide is taken in large amounts. Avoid taking several iodine-containing products together.
Contraindications
- Known allergy or sensitivity to iodine.
- Dermatitis herpetiformis or hypocomplementaemic vasculitis.
- High-dose use should be avoided in people with untreated thyroid nodules or overactive thyroid unless directed by a doctor.
Side Effects
At normal supplement amounts side effects are rare. Larger amounts may cause a metallic taste, stomach upset, increased saliva, acne-like rash, swelling of the salivary glands and changes in thyroid function (either overactive or underactive).
Get urgent medical help if you have swelling of the face, lips or throat, difficulty breathing, a severe rash, fever with joint pain, or symptoms of thyroid imbalance such as a racing heartbeat or severe tiredness.
Pregnancy and Lactation
Adequate iodine is important during pregnancy and breastfeeding for the baby’s brain and thyroid development, and supplements at the recommended amount are generally advised. Avoid high doses, which can affect the baby’s thyroid, unless prescribed.
Precautions and Warnings
People with thyroid disease, kidney problems or a history of iodine sensitivity should ask a doctor before taking iodide supplements. Do not exceed the recommended amount, as too much iodine can also upset thyroid function. Iodide may affect thyroid scans; tell your doctor before any thyroid test.
Overdose
Taking a large amount may cause burning in the mouth and throat, stomach pain, vomiting, diarrhoea and, later, thyroid problems. Seek medical help, especially if a child has swallowed supplements.
Therapeutic Class
Mineral supplement (trace element, iodine source).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.