🔬 The science, kept simple
Your thyroid gland traps iodine to build the hormones that set the speed of your whole metabolism... energy, warmth, heart rate, even mood. The soil in much of the world is iodine-poor, which is why goiter was common until iodized salt arrived.
Why you need it: Thyroid hormone production; especially critical in pregnancy for the baby's developing brain.
Daily target: About 150 micrograms a day for adults, 220 in pregnancy.
🥇 Best food sources, ranked
- Iodized salt ... about 76 mcg per quarter teaspoon
- Kelp and dulse (sparingly) ... kelp can exceed 500 mcg per gram... use lightly
- Dairy and kefir ... about 60-90 mcg per cup
- Prunes ... about 13 mcg per 5 prunes
- Lima beans ... about 8 mcg per cup
Figures are approximate, in the style of USDA FoodData Central; real foods vary with soil, variety, and cooking.
⚖️ Worth knowing
Both too little AND too much iodine can upset the thyroid. Kelp is potent... a little goes a long way, and people with thyroid disease should ask their doctor before adding seaweed or iodine supplements.
Matters most for
Educational information, not medical advice. Talk with your doctor before supplements, especially with kidney, thyroid, or heart conditions or in pregnancy.