Low-Iodine Diet
A low-iodine diet restricts dietary iodine intake to less than 50 micrograms (mcg) per day. It is primarily prescribed in the weeks before radioactive-iodine-treatment for hyperthyroidism to ensure the thyroid is starved of iodine and will therefore maximally absorb the therapeutic radioactive dose.
Foods Permitted (Low Iodine)
- Non-iodized salt
- Egg whites (not yolks — yolks are high in iodine)
- Fresh or frozen vegetables
- Herbs and spices
- Vegetable oils
- Sugar, honey, maple syrup (up to 2 tbsp)
- Jams and jellies
- Unsalted nuts and nut butter
- Lemonade, beer, wine
- Moderate portions of unprocessed beef, chicken, turkey, veal, lamb
- Fruit and fruit juices
Foods to Avoid
- Iodized salt
- Seaweed and kelp
- Fish and shellfish (unless iodine-free)
- Dairy products
- Egg yolks
- Red food dye
- Blackstrap molasses
- Carrageenan (food additive)
- Baked goods with iodate dough conditioners
- Iodine supplements
Balancing Other Nutrients on a Low-Iodine Diet
Getting enough calcium, vitamin-d, selenium, and iron becomes harder when dairy, seafood, and eggs are restricted. Working with a dietitian is advised, and supplementation may be necessary.
Duration
Typically a short-term protocol (1–2 weeks pre-treatment). Long-term iodine restriction is not recommended for most patients.
Reference
The american-thyroid-association publishes detailed patient guidance on following a low-iodine diet.