Salt Your thyroid needs iodine to work well. Most people in the U.S. easily get enough of this element from their diet, usually through fish and dairy products. Make sure you’re using iodized table salt at home. You can tell by looking at the label. Sea salt and the salt used in packaged or processed foods usually aren’t iodized. Leafy Greens Spinach, lettuce, and other leafy greens are great sources of magnesium, an all-star mineral that plays a huge role in your body processes. Fatigue, muscle cramps, and changes in your heartbeat could be signs that you're not getting enough. Nuts Cashews, almonds, and pumpkin seeds are excellent sources of iron. Brazil nuts help your thyroid in two ways. Not only are they a good source of iron, but they're also rich in selenium, another mineral that supports the thyroid. Just a few each day give you the selenium you need. Seafood Fish, shrimp, and seaweed are great sources of iodine. You need iodine for a healthy thyroid, but avoid large amounts of kelp if you have a thyroid problem. Kelp is high in iodine and may make your condition worse. Kale Could kale, that superstar among superfoods, actually not be quite so awesome? Kale is a mild goitrogen -- in rare cases it prevents the thyroid from getting enough iodine. But kale should not be a problem for you unless you get very little iodine in your diet and you’re eating large amounts of kale. This is also the case for cabbage, broccoli, cauliflower, and Brussels sprouts. Soy In rare cases, some of the chemicals found in soy products like soy milk or edamame could hurt the thyroid’s ability to make hormones, but only if you’re not getting enough iodine and you eat large amounts. Just like with kale, if your iodine levels are OK, you probably don’t need to worry about eating soy. Organ Meats If you eat organ meats like kidneys, heart, or liver, you might get a lot of lipoic acid, which is a fatty acid found in these and some other foods. You can also buy it as a supplement. But if you get too much, it could disrupt the way your thyroid works. Lipoic acid could also have an effect on any thyroid medicines you take. Gluten and Your Thyroid Gluten is a protein found in wheat, rye, and barley. Unless you have been diagnosed with celiac disease, it probably won’t affect your thyroid. Gluten can damage the small intestines of people with celiac disease. That damage can cause serious problems and is linked to an increased risk of Hashimoto’s disease (which leads to an underactive thyroid) and Graves' disease (which leads to an overactive thyroid). If you have celiac disease, sticking to a gluten-free diet may help prevent these thyroid diseases. Thyroid Medication and Your Food The foods you eat can affect your thyroid medicine. They can slow down how fast or how well your body absorbs medicine. Take medicine on an empty stomach, preferably in the morning. Some vitamins and antacids can also prevent your medicine from working. Ask your doctor or pharmacist for more information. Source