Best Natural Thyroid Supplements [+ Foods For A Healthy Thyroid]

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Hypothyroidism, or underactive thyroid, is a health problem that is affecting millions of individuals worldwide. Although taking medications to treat it is often necessary, there are some natural ways you can try to improve thyroid health through proper lifestyle, diet, and supplementation.
So if you are suffering from an underactive thyroid or looking to avoid this problem, here is what you need to know about hypothyroidism, the best natural thyroid supplements and foods for a healthy thyroid.

What Is Hypothyroidism?

Hypothyroidism is a disorder that indicates that the thyroid gland is underactive, which means that it is not producing enough thyroid hormones.
This problem can affect men and women although it is most common in women, especially older women.

The thyroid is a small butterfly-shaped gland located on the front of the neck, that releases 2 main thyroid hormones: triiodothyronine (T3) and thyroxine (T4). These hormones play an important role in regulating metabolism and organ function. They help the body to turn food into energy, stay warm and regulate sleep. They also help to keep the brain, heart, muscles and other organs healthy.

Symptoms of Hypothyroidism

Symptoms of an underactive thyroid (or hypothyroidism) tend to develop slowly, which is why sometimes it can take years before you notice it.
Some of the signs and symptoms that can indicate an underactive thyroid include:

  • Feeling tired (fatigue)
  • Feeling cold
  • Constipation
  • Depression
  • Weight gain
  • Dry skin
  • Aching muscles and joints

Having an enlarged thyroid gland (also called goiter) is also often a sign of low thyroid function.

Hypothyroidism Diagnosis

The only way to make sure that you have hypothyroidism is through a blood test that will measure the levels of THS and T4 hormones. If THS is high and T4 is low, it usually means that you have hypothyroidism.

This is because when thyroid hormone levels are low, the pituitary gland (which is located at the base of the brain) releases thyroid-stimulating hormone (THS), which in turn causes the thyroid gland to release its T3 and T4 hormones.
So when THS levels are high and T4 is low, it usually means that the thyroid gland is not producing enough hormones and it is therefore a sign of low thyroid.

Causes Of Hypothyroidism

These are the most common causes of hypothyroidism:

Autoimmune disease

Hashimoto’s disease is one of the most common causes of hypothyroidism. Also known as Hashimoto’s thyroiditis, it is a condition in which the immune system attacks the thyroid gland. Because of this, the thyroid gets damaged (inflamed) and stops producing enough hormones.

Lack of iodine and selenium

Not consuming enough iodine and selenium can also cause hypothyroidism. This is because these two trace minerals are needed by the thyroid gland to produce the right amount of hormones.

Unhealthy Gut

Gut health is closely related to thyroid function. People suffering from leaky gut syndrome, gut inflammation or infections, parasites, or chronic digestive issues including diarrhea and constipation, are much more likely to experience thyroid problems.

Gut inflammation can be caused by allergies (such as to gluten or dairy), by regularly eating highly processed foods, not having enough “good” gut bacteria and too much stress.

So although hypothyroidism does negatively affect digestive health, the opposite is also true as poor digestive health can lead to hypothyroidism.

It is therefore essential to take steps to repair gut health in order to improve thyroid health.


Postpartum thyroiditis is a condition that can affect some women within the first year after giving birth.

This condition often has 2 phases. At first, the immune system attacks the thyroid gland and causes it to become overactive. Later on, as the thyroid gland gets damaged, symptoms of hypothyroidism can start to appear.

Postpartum thyroiditis is more likely to affect women who have a family history of autoimmune diseases or thyroid problems, as well as those who have high levels of anti-thyroid antibodies or already have type 1 diabetes.


When we are stressed, our body goes into “fight or flight” mode. The adrenal glands, situated on the top of our kidneys, release stress hormones including adrenaline and cortisol. These hormones increase our heart rate, breathing, blood pressure, blood sugar, and energy so we can respond to that stressful situation. But at the same time, these hormones slow down other functions including the immune system, digestion, as well as the production of thyroid hormones. This is because these functions are not considered vital to respond to that stressful moment.

So if we are stressed just for a little while, that’s OK. When the stressful situation is over, normally everything gets back to normal. But in our modern day lives, we are constantly stressed and so often end up suffering from chronic stress. This means that all our bodily functions get affected, including the thyroid that ends up producing too little hormones, potentially leading to hypothyroidism.

However, there are many ways you can try to reduce stress naturally. To learn more about it, you can check out our post about adaptogens and stress.

A side effect of certain medications

Some medications such as those to treat cancer, heart and psychiatric conditions, can cause the thyroid to become underactive. In that case, it is often called drug-induced hypothyroidism.


Research has shown that genetics plays an important role in the potential development of thyroid problems. This often means that if we have a family history of autoimmune thyroid disease or other thyroid problems, our chances of being affected increase.

Foods To Eat For A Healthy Thyroid

We truly believe that having a healthy diet is the best natural way to treat hypothyroidism. Eating a balanced diet is vital for optimum health, but there are some foods that can be particularly beneficial to treat low thyroid.
Here are the best foods for a healthy thyroid.


Iodine is a trace mineral (the body only needs a small amount of it) that is essential for the production of thyroid hormones. It is also needed for the development of a baby’s brain during pregnancy and beyond.

Here are the daily requirements of iodine:
Adult = 150 micrograms (mcg)
Pregnant and breastfeeding women = 200 micrograms (mcg)

Foods rich in iodine:
– Fish such as cod
– Shellfish such as shrimp, prawns
– Dairy products such as milk, yogurt, cheese

So people who don’t eat these foods regularly, including vegetarians and vegans, are more likely to have an iodine deficiency.

A good way to avoid iodine deficiency is to replace regular table salt with iodized salt, which contains added iodine.

Seaweed is indeed a good source of iodine, but as it contains a lot of it, you should be careful not to consume too much.

You should keep in mind that having too little or too much iodine can both cause thyroid and health problems.



Selenium is another mineral that the thyroid gland needs to properly produce thyroid hormones. It is also important for reproductive health, DNA production, and to protect from infections. Moreover, it acts as an antioxidant as it helps protect the cells from free radicals.

Foods rich in selenium:
– Nuts such as Brazil nuts and walnuts
– Fish such as tuna, cod, halibut, and herring
– Mushrooms
– Beef
– Poultry
– Liver

Like iodine, having too little or too much selenium in the body can negatively affect your health.



Eating enough fiber is essential for proper digestion. And having a healthy digestive system is necessary for “good” gut bacteria to thrive.

Since we know that gut health is related to hypothyroidism, eating a balanced diet that includes fiber-rich foods such as a variety of vegetables, fruits and whole-grains is very important. These promote regularity and prevent constipation.

Foods To Avoid

Gluten (if you have Hashimoto’s disease)

Studies show that people who have an autoimmune disease are more likely to be affected by other autoimmune diseases.

That is the case with people suffering from Hashimoto’s disease who often also have celiac disease. Those suffering from celiac disease cannot eat gluten and so avoiding it could also benefit those affected by Hashimoto’s thyroiditis.



Goitrogens are chemicals that are naturally present in some plant-based foods. Eating these too often and in large amounts can disrupt thyroid function and cause swelling of the thyroid gland (goiter). This is because goitrogens can prevent the thyroid gland from releasing hormones and can also reduce the body’s ability to use iodine.

Goitrogen rich foods include:
– Cruciferous vegetables such as cauliflower, broccoli, Brussels sprouts, kale, turnips, radishes…
– Fruits such as strawberries, peaches, cherries, plums…
– Soy products such as soy milk, edamame, tofu, tempeh,

However, cooking these foods reduces their goitrogenic content. So you don’t need to completely eliminate them from your diet. Just make sure you don’t eat them raw and in large amounts every day. Steaming is usually the best way to go.

Best Natural Thyroid Supplements


Ashwagandha (Withania somnifera), also called Indian Ginseng, is a plant that has been used for centuries in Ayurveda and that is known to be a powerful adaptogen. It is extremely effective at fighting stress and improving thyroid function. It has also been proven to increase energy, promote restful sleep, reduce inflammation and support digestive health, which is why it is one of the best natural supplements that can be taken to treat hypothyroidism.

Possible side-effects of ashwagandha:
Ashwagandha is usually safe to take although taking more than the recommended dosage can cause an upset stomach, vomiting, and diarrhea.

Where to buy ashwagandha?
Good quality ashwagandha supplements (sometimes labeled as KSM-66) can be bought online.
Some of the best high-quality ashwagandha supplements we know include this one from Gaia herbs or this other organic one available on Amazon.



As selenium is a mineral that is essential for the production of thyroid hormones, taking it as a supplement can be beneficial especially if your diet does not include selenium-rich foods.

As well as protecting the thyroid from damage by acting as an antioxidant, selenium plays an important role in turning the hormone T4 into T3.

Research shows that selenium is better absorbed and more effective in organic form (which means when it comes from a food source), and those suffering from autoimmune thyroiditis can greatly benefit from it.

Selenium has also been shown to help reduce the levels of thyroid antibodies. Thyroid antibodies are made by the immune system to fight bacteria and viruses, but in the case of autoimmune disease, these antibodies start attacking healthy cells as well.

Possible side-effects of selenium:
At the recommended dosage, selenium is usually safe to take. But taking too much of it can be toxic and cause symptoms including nausea, vomiting, abdominal pain, diarrhea, hair loss, brittle nails, peripheral neuropathy, and a smell of garlic in breath and sweat.

Where to buy selenium?
As it is best to take selenium in its organic form, this high-quality whole food selenium supplement from MegaFood is a great option.



Research shows zinc deficiency is associated with hypothyroidism and so zinc is another trace mineral that the thyroid needs to maintain proper hormone production.

Like selenium, zinc also plays a role in the conversion of T4 into T3. On top of that, zinc also supports immune function, gut health, wound healing, and protects from oxidation.

Symptoms of zinc deficiency include brittle nails, loss of taste and smell, low immunity (getting sick regularly), hair loss, slow wound healing, diarrhea, loss of appetite.

As always, it is best to ask your doctor before you start taking a zinc supplement, especially if you are taking medications, suffering from other health problems, pregnant or breastfeeding.

Possible side-effects of zinc:
Zinc supplements are usually safe to take at the recommended dosage, but taking it in large amounts for a prolonged period of time can be harmful and cause stomach cramps, nausea, vomiting, diarrhea, headaches.

Where to buy zinc?
We believe that natural, whole food supplements are a much more effective and healthier alternative to synthetic supplements. If you want to know why, you can check out our short post where we explain the difference between natural and synthetic supplements.

Here is a great natural, organic whole food zinc supplement that is worth trying.


Vitamin D3

Vitamin D deficiency has been linked to hypothyroidism as studies have shown that people suffering from thyroid disease usually had much lower levels of vitamin D compared to normal subjects. This makes sense considering the fact that vitamin D, also called the sunshine vitamin, plays an important role in immune function and hypothyroidism is closely linked to autoimmune diseases such as Hashimoto’s.

Vitamin D (cholecalciferol-D3) is a fat-soluble vitamin that helps the body to absorb calcium and phosphorus.
Normally, the body creates vitamin D when the skin is exposed to sunlight. But since a lot of people do not get enough sun exposure, and very little vitamin D is present in food, vitamin D deficiency is a common problem. It is therefore often necessary to take it as a supplement.

Possible side-effects of vitamin D:
Having too much vitamin D is usually rare but can happen is you take vitamin D supplements in very high doses for a long time. Since vitamin D helps in calcium absorption, having too much vitamin D can cause the body to absorb too much calcium and produce some serious symptoms including stomach ache, nausea, vomiting, diarrhea or constipation, low appetite, bone loss, and kidney failure.


Final Thoughts

Treating hypothyroidism without medications can’t always be avoided. However, it is possible to help yourself and make some changes in your life and diet that can result in improved thyroid function.

Having a well-balanced diet and staying active is vital for optimum health. Try avoiding foods that are highly processed as it will help to prevent weight-gain and oxidative stress often associated with thyroidism. And instead, try to eat more of the foods for a healthy thyroid we have mentioned earlier.

If you think you might benefit from taking any of the best natural thyroid supplements listed above, it is best to talk about it with your doctor first and make sure that you choose a product that is high quality and as natural as possible for the best results.

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