Whether you eat it in a sushi roll, in a salad, or on its own as a salty snack, it’s a great source of iodine, which your thyroid gland needs to work properly. But too much iodine at once can make you break out. Most adults need 150 micrograms a day, though pregnant and breastfeeding women need more. If you eat a balanced diet, it’s hard to get too much. Along with seaweed, you can get iodine from foods like fish, dairy products, and iodized salt.