Updated: Mar 18
What does the thyroid do in the body?
Your thyroid plays a role in a wide variety of functions in the body including your metabolism, body temperature, heart rate, fertility, and even digestion.
If your thyroid is not functioning correctly you can experience fatigue, constipation, hair loss, frustrating weight gain, anxiety, and trouble sleeping.
Since these symptoms are also tied to many other conditions, the best way to determine if your thyroid is functioning correctly is through lab testing. To get accurate information, you need to test more than just your TSH level.
Did you know your TSH level is not actually produced by the thyroid? So why is it the first thing we test for when checking for an abnormal thyroid?
TSH is produced by the pituitary gland in the brain and its role is to stimulate the thyroid to produce thyroid hormones T4 and T3. I always recommend a full thyroid panel to make sure we have an accurate look at how the thyroid is functioning.
Comprehensive Thyroid Testing
A full thyroid panel includes pituitary (brain) hormone TSH as well as the thyroid hormones - T3, T4, reverse T3, and thyroid antibodies. We can look at the communication between the brain and thyroid when a full thyroid panel is done.
You can ask your doctor to order a full thyroid panel and go through insurance, or you can order your own thyroid panel with Ulta Labs, a popular nationwide laboratory. Ulta Labs has their Thyroid Panel - Basic Plus for $79. Find the thyroid panel and order it here.
It is important to have support and the right health care team behind you! Find a health professional who can help you understand the process and guide you through a supportive and natural healing process that you feel comfortable with.
In this article we will cover what foods and nutrients are best for supporting thyroid health. This article benefits women who want to prevent thyroid disease, women who have thyroid disease, and women who no longer have a functioning thyroid.
What if you don't have a functioning thyroid anymore?
If you no longer have a functioning thyroid, then you are actively taking thyroid medication and your body still needs to convert T4 into T3 active thyroid hormone, so these nutrients are important for all.
Let’s get started with the food and nutrients that are most important for thyroid health!
Each of these nutrients listed below play an important role in the function of your thyroid, however you need to make sure you are replenishing all nutrients in order to prevent imbalances and deficiencies. For example, supplementing with iodine if you have low selenium can actually make thyroid disease worse.
Selenium is an important nutrient because it is needed for the enzyme that converts T4 hormone into the active T3 hormone. If your body is deficient in selenium then hypothyroidism can develop due to low levels of thyroid hormone available.
Selenium is found in liver, seafood, and red meats. Selenium can also be found in Brazil nuts, but the amount present depends on the soil content. Unfortunately the range of selenium in 1 ounce of Brazil nuts can range from 55 mcg to 550 mcg.
Here is the supplement I recommend in my practice: Ecological Formulas Kelp
Iodine is essential for thyroid hormone production because the thyroid gland actually uses iodine with the amino acid tyrosine to create thyroid hormone. We only need about 150 micrograms (mcg) of iodine per day for optimal thyroid function.
3 oz. of cod has 99 mcg iodine 3 oz. shrimp has 35 mcg iodine
In the past, iodine deficiency was such an epidemic that the government ruled table salt needed to be fortified with iodine. This is why we have “iodized salt” as your general table salt.
It is important to know that too much iodine can stop thyroid synthesis, which is why many women with thyroid disease should avoid using iodized salt and other fortified foods to prevent excess iodine levels.
Avoiding fortified foods and choosing a high quality supplement with iodine and selenium will help to keep your nutrient levels balanced.
Here is the supplement I recommend in my practice: Ecological Formulas Kelp
We call this a vitamin, but vitamin D functions more as a hormone in our bodies. This is why vitamin D deficiencies are significant and associated with autoimmune conditions, including Hashimoto’s (thyroid autoimmune disease).
The best way to get vitamin D is through our skin’s own production. However, it depends on where we live in the world, if we are able to get enough UV light from the sun to produce sufficient levels of vitamin D in our body. Here in the Midwest it is not likely we can make enough vitamin D outside of a couple of summer months.
Also, if you are like me and fair-skin then being in direct sunlight with no sunscreen for the 30 minutes necessary to produce enough daily vitamin D, is not a great idea (or pretty for that matter). If you have darker skin you need to be in direct sunlight with no sunscreen for a longer period of time, potentially 2 hours per day to make enough vitamin D.
This is why vitamin D supplementation is recommended for most adults. Vitamin D is fat-soluble meaning you should take this supplement with a fat-containing meal, ideally later in the day for optimal absorption. Most adults benefit from taking 2000 IU vitamin D3 daily. I also recommend that you find a supplement that includes vitamin K2, because it works with vitamin D and calcium to be absorbed into bones and maintain bone health.
Omega 3 Fatty Acids
There are a few different types of essential fatty acids that our body needs. Because of our diet and high prevalence of chronic inflammation, our balance of omega-3 fatty acids is depleted. Fatty acids are necessary for all of our cell membranes, energy production, and brain health.Omega-3 fats are specifically involved in the anti-inflammatory pathways in the body.
If we have inflammation present in our bodies (which we all do) and not enough omega-3 fatty acids, our thyroid function can actually decrease because it is needed for thyroid receptors (converts T4 to T3).
The best sources of omega-3 is cold water fatty fish like salmon, sardines, herring, and oysters. Some plants also have omega-3 sources, but the plant form still needs to be converted into omega 3’s EPA and DHA form, which the body does not do well.
When choosing an omega-3 supplement, make sure to find one that is third party tested and free of heavy metals, pesticides, solvents, PCBs, and other contaminants.
Magnesium is a powerful mineral that participates in over 300 enzymatic reactions in the body. It is estimated that up to 75% of the US adult population is low in magnesium (1)
You can find magnesium in green vegetables, especially dark leafy greens, because it is a component of chlorophyll (remember middle school science).
½ cup serving of cooked spinach is about 78 mg of magnesium.
1 cup of brown rice has 86 mg of magnesium.
1 ounce of almonds has 77 mg of magnesium.
A fun fact I learned playing around in the kitchen is that sunflower seeds are also high in chlorophyll and therefore magnesium. If you bake cookies or muffins with sunflower butter, they will turn a bright green color as they cool! This is the chlorophyll in the seeds.
The unfortunate fact with magnesium is that we are seeing an increase in this mineral depletion in our bodies because our plants need to get their magnesium from the soil, and soil quality in the United States has continued to deplete over time. Therefore our magnesium intake has suffered.
There are many types of magnesium if you are looking for a supplement. Magnesium glycinate is easy to absorb and digest. If you have issues with constipation you can try magnesium citrate, another good form that can have a slight laxative effect.
Zinc is another nutrient involved in the synthesis of thyroid hormone and also one of the co-factors needed for conversion of thyroid hormone T4 into active T3. Zinc is also a big player in immune health as well as hormone production.
The World Health Organization (WHO) estimates that about 31% of the world’s population is deficient in zinc (4). So, why would that be?
Zinc is found in shellfish and red meats like beef. The form of zinc present in whole grains, legumes, and nuts is difficult for the body to absorb because it binds with phytates (also present in these foods). So they are not a reliable source of zinc.
If you notice a trend here, if you don’t eat much seafood and limit your red meat then you could be lacking many of the essential nutrients for thyroid function.
Here is the zinc supplement that I recommend in my practice: Megafood Zinc
Iron plays a role in supporting thyroid function and maintaining a balance of T4 and T3 hormones. If you have low iron levels, it can be difficult to heal hypothyroid disease and maintain stable thyroid levels. Iron is also an important player in immune health, like zinc and vitamin D.
The World Health Organization (WHO) predicts that about 25% of the world’s population is deficient in iron (5). That’s a lot of people!
Iron is found as two forms in food, heme- and non-heme iron. Heme iron has the best absorption and is present in animal products (liver, beef, chicken, eggs). Non-heme iron is found in plant sources, but it can be easily blocked by other nutrients like phytates.
Vitamin C can increase absorption of non-heme iron, so if you are trying to increase your iron levels make sure to include an iron source and vitamin C source at every meal. For example, make a smoothie that has a large handful of spinach (high in iron) + 1 cup strawberries (high in vitamin C).
Iron supplements can cause stomach irritation if they are synthetic form and taken on an empty stomach. Here is a whole food iron supplement I recommend in my practice that has been well liked. Gaia Herbs PlantForce Liquid Iron
When Should You Test Your Thyroid?
If you are actively taking thyroid medication it is recommended to test every 6-12 months to monitor levels. If you have a history of abnormal thyroid levels it is recommended to test every 3-6 months until levels stabilize.
If you have not identified what is causing stubborn symptoms of fatigue, constipation, hair loss, frustrating weight gain, anxiety, and trouble sleeping; I recommend additional testing.
Additional Labs to Test:
Reverse T3 Measurement of reverse t3 can help identify an inflammatory condition blocking proper thyroid function. Reverse T3 is a byproduct of thyroid hormone metabolism and increases with high stress or inflammation present in the body.
Thyroid Antibodies (TPO, TgAb) Measurement of thyroglobulin antibodies is useful in the diagnosis and management of autoimmune conditions Hashimoto's thyroiditis and Graves Disease..
Cortisol Cortisol is best tested through saliva and should be collected periodically in a 24-hour period in order to have the most comprehensive and helpful reading. Cortisol will fluctuate throughout the day, so we want to make sure it is rising and falling in a normal pattern. Elevated cortisol levels can be another reason why progesterone levels are too low.
DUTCH Hormone Panel
This is by far my favorite and most comprehensive test out there for hormones. I run this test in my practice often and has been extremely helpful in identifying the hormones and detoxification pathways that need to be supported for healing and balance. The DUTCH panel is a simple at-home collection since it uses dried urine as the sample. You can collect your sample at home and send it back to the lab through the mail. This test should be interpreted by an experienced health provider for you to get the most out of the results. You can learn more and order the DUTCH panel, here.
Again, it is important to have support and the right health care team behind you! You don’t have to go through this alone. Find a health professional who can help you understand the process and guide you through a supportive and natural healing process that you feel comfortable with.
Do I need to eliminate certain foods from my diet?
If you are sensitive or intolerant to foods, then yes those foods should be avoided in a healthy thyroid diet. However, most foods are perfectly healthy and safe to include in your diet.
I’ve heard goitrogens found in cruciferous foods should be avoided if you have thyroid disease. Is that true?
There is truth that foods high in goitrogens, like cruciferous vegetables, can affect thyroid function if eaten in high doses. The key here is “high doses”. Also, if you are deficient in iodine you may have an increased sensitivity to goitrogens (6). I highly encourage monitoring nutrient levels and supplementing as needed to maintain nutrient balance in the body.
The good news is that cruciferous vegetables have been studied extensively for their health benefits and if eaten moderately 1-2 servings per day will not interact with thyroid function in those with thyroid disease.
Cruciferous vegetables include: broccoli, cauliflower, kale, cabbage, and Brussels sprouts. These foods are high in nutrients that have actually been studied to balance estrogen and promote healthy detoxification pathways. This is why I do not recommend that women with thyroid disease eliminate cruciferous vegetables from their diet, but instead to maintain a steady intake of 1-2 servings per day.
Eating a Balanced, Healthy Diet for a Healthy Thyroid
If you haven’t downloaded my “Tracking Hormones Guide” here, I recommend you do so now. This guide will help you set up tracking so that you are able to monitor how foods affect your body. You will have the right information you need to tweak your diet for optimal health!
A Whole Food, Low Sugar Diet
Cut the sugar. Let's not forget you have got to cut the sugar, cut the alcohol, and bring on the fibrous vegetables and high-quality proteins and fat.
Work on increasing fiber in your diet with the first goal of 30 grams per day. Choose foods like berries, greens, flaxseed, chia seed, whole grains, avocado, and almonds.
Eat high quality protein with your meals to help balance blood sugar and keep you full. For animal proteins make sure to choose organic. If you are having trouble getting enough protein in your day, here is a clean protein powder I recommend to clients.
Use spices and herbs in cooking. Both spices and herbs are what I like to call, food medicine. They have specific roles and benefits in our metabolism, detox, hormone production, and more. Include foods like ginger, turmeric, cinnamon, garlic, rosemary, basil, oregano, etc.
Daily Health Supplement Regimen
Omega-3 Fish Oil with at least 1000 mg EPA + DHA
Vitamin D3 with vitamin K2 - 2000 IU daily
Magnesium - 350 mg daily
For high-quality supplements, I recommend using a certified and trusted site that gets their product directly from practitioner-approved companies. Fullscript is an online supplement dispensary where you can find many practitioner-approved, third-party tested brands. Sign up for a free account here.
Live confident & comfortable in your body!
- Liz, RD
Liz Riesen, Registered Dietitian
specializes in digestive and hormone imbalances. Often these conditions coexist and share common disruptive symptoms including mood changes, bloating, pain, irregular cycles, inflammation, and more. Liz is trained in identifying and healing food sensitivities, as well as balancing hormones naturally through nutrition and lifestyle.
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