Iodine Supplements: Benefits, Dosage and Safety
Iodine supplements matter mainly in pregnancy and for people who don't use iodized salt or eat dairy or seafood. Iodine is needed to make thyroid hormones, but too much can cause thyroid problems, so avoid kelp and high-dose 'thyroid support' products.
Evidence at a glance
| Use | Grade | What the research shows |
|---|---|---|
| Preventing deficiency in pregnancy | A | Essential for the baby's brain development. |
| Thyroid 'support' in people with adequate intake | D | Extra iodine can trigger thyroid problems. |
A: strong, consistent human evidence · B: moderate · C: limited or mixed · D: good evidence of no benefit.
The thyroid uses iodine to make hormones that control metabolism.
How to take it
Most prenatal vitamins contain 150 mcg. Otherwise, iodized salt usually covers needs. See thyroid supplements.
Safety and interactions
Excess iodine can cause hypothyroidism, hyperthyroidism or thyroiditis, especially in people with existing thyroid disease.
Always tell your doctor and pharmacist about the supplements you take. Check combinations with our interaction checker.
Sources
This page is for education and is not a substitute for advice from your doctor. Read our medical disclaimer.