The key nutrients for thyroid health are iodine and selenium. It is best to get both of these nutrients from food sources. Many people have removed iodized salt from their diet and there are very few other sources that are part of the Standard North American Diet. Interestingly, dairy has iodine in it due to the cleaning agent used on the equipment that processes dairy. This has been shown to be a primary iodine source in today’s population. Cod is also particularly high. Seaweeds are by far the highest source of iodine however nori is not as high but consumed the most. Integrating kelp, kombu, arame, wakame and other sea vegetables is an excellent way to optimize iodine.
Selenium is found in most multi-vitamins and this is part of why I don’t recommend use of these. Supplementing selenium can be dangerous long-term due to toxicity. You can get your levels checked and maintain adequate selenium through eating 1-2 brazil nuts daily. Other sources are fish/shellfish, kidney, mushrooms, meat and poultry.
Adequate amounts of zinc, magnesium, vitamin A, C, D, B12 and B2 are also crucial for proper function. Magnesium glycinate is a good form and safe to supplement. Cod liver oil is a good way to get enough bioavailable vitamin A and D along with adequate sunlight exposure. omnivores will likely get enough B12 but it’s always good to check as health conditions related to low B12 can be debilitating. Ensuring iron ranges are optimal is also important as this is often too low but also can be too high. I check a number of markers beyond hemoglobin and ferritin in order to get an accurate iron profile. Clams are highest in iron and magnesium. Zinc can be found in oysters, liver, crab, beef and lobster. Vitamin C is highest in red pepper, kiwi and citrus fruits.
Avoiding goitrogens will optimize thyroid health and iodine levels. The best practice is to simply limit raw goitrogens to a couple servings per week. Cooking these foods reduces the harm for example cooking yucca reduces goitrogens by 90%. Cooking kale reduces them by 33%. Many of these foods have high nutrient densities so we don’t want to remove them completely. nitriles also have an effect on the thyroid. A great example of this is sauerkraut reduces nitriles but is cabbage which is a goitrogen. The benefits of raw sauerkraut outweighs the risk in this case and this is partially because nitriles are more of a concern than goitrogens.
As you can see there are grey areas but keeping it as simple is key. Except for sauerkraut keep steaming and cooking these foods. In another article I’ll talk more about the autoimmune diet, which in many cases is key to recovering vitality.