Iodine
What it is
Essential for thyroid hormone production and fetal brain development. WHO estimates deficiency affects over 2 billion people and is the most common preventable cause of intellectual disability. Excess iodine is equally harmful — it can trigger thyroid dysfunction. Test urinary iodine and thyroid panel before supplementing. Iodised salt and seafood are usually sufficient.
Dose
150–220 mcg/day if deficient; test urinary iodine and thyroid panel first; do not exceed 1,100 mcg/day
Time of day & tips
Take with food at any time of day. Space 4 hours from levothyroxine. Do not take with high-calcium foods, as calcium may impair absorption. Test levels before starting.
Compare or learn more
Compare with another supplement →
Browse by symptom →
Open the full interactive view →