Iodine deficiency is making a comeback. Many people have cut iodized salt, don't eat seafood, and avoid dairy. If you're looking for iodine supplements, here's what you need to know.
Common Iodine Sources in Supplements
Kelp/Seaweed - Highest concentration, most variable - Amounts can range from 100mcg to 5000mcg+ - Some kelp supplements are way too strong - Risk of excess iodine from cheap products
Potassium Iodide - Most controlled, predictable - Standard form in multivitamins - Easy to dose accurately - What's in iodized salt
Prenatal Vitamins - Should contain 150-220mcg - Not all do. Check the label. - Critical for fetal brain development
Thyroid Support Formulas - Often include iodine - Combined with selenium, zinc, tyrosine - Amounts vary. Check carefully.
How Much Do You Need?
RDA: 150mcg for adults, 220mcg for pregnant women
Upper limit: 1100mcg daily (easy to exceed with kelp)
Signs you might need more: - Fatigue and weight gain (thyroid-related) - Dry skin, feeling cold - Brain fog - Diet lacking seafood, dairy, and iodized salt
Signs of too much: - Metallic taste - Thyroid problems (can go either way) - Nausea, diarrhea
Who Should Be Careful
Hashimoto's thyroiditis - Iodine can worsen it in some cases. Work with your doctor.
Anyone on thyroid medication - Iodine affects thyroid hormone production. Don't supplement without medical guidance.
Most people on a varied diet - Probably getting enough already. A single serving of fish or dairy often covers the RDA.