Nutrition for Hashimoto’s Thyroiditis

Hashimoto's

Hashimoto’s thyroiditis is a condition where the immune system mistakenly attacks the thyroid gland. Over time, this can reduce thyroid hormone production and lead to hypothyroidism.

Common symptoms can include weight gain, dry skin, feeling cold, poor memory, fatigue, sore muscles and joints, depression and reduced libido. Diagnosis usually starts with a GP, who may test thyroid antibodies, thyroid stimulating hormone and thyroxine levels.

Medical Management Comes First

Nutrition can play a role in supporting thyroid health, but it does not replace medical care. Some people need medication, while others may benefit from addressing gaps in their diet.

Levothyroxine is one of the most common medications used for hypothyroidism. When dosed well, it can help manage many symptoms. However, the dose may need to change over time.

Food, coffee, calcium and iron can affect how well levothyroxine is absorbed. For this reason, it is usually best to take it away from food, often 30–60 minutes before breakfast.

Start With Overall Diet Quality

Fruits and vegetables

Before focusing on single nutrients, it helps to look at the overall diet. A nutrient-rich diet supports general health and may also help thyroid function.

An anti-inflammatory style of eating may be useful too. Hashimoto’s thyroiditis involves inflammation, so a diet that supports lower inflammation may help. A 2024 cross-sectional study found that closer adherence to an anti-inflammatory diet was linked with better thyroid markers in people with Hashimoto’s.

Iodine

The thyroid needs iodine to make thyroid hormones. However, iodine deficiency is not overly common in developed countries because foods like salt are often fortified.

Iodine is important, but too much can worsen hypothyroidism. Because of this, it is worth being careful with high-dose iodine supplements unless there is a clear reason to use them.

Selenium

A lot of the body’s selenium is found in the thyroid. Low selenium intake may contribute to thyroid issues, and some research suggests selenium supplementation can reduce symptoms and improve wellbeing, especially in people who are deficient.

This does not mean selenium fixes everything. However, it can be useful in the right context.

A common supplement range is around 100–200 micrograms per day. From food, one to two Brazil nuts per day can be enough. It is also possible to overdo selenium, especially with large amounts of Brazil nuts or high-dose supplements.

Myo-Inositol and Selenium

One of the more interesting areas in recent research is combining myo-inositol with selenium. Studies have shown that taking both together can reduce thyroid stimulating hormone more than selenium alone.

This does not make it a magic solution, but it may be a helpful option in some cases.

Goitrogens

Goitrogens

Goitrogens can interfere with iodine uptake, which is why some people recommend avoiding them. Foods higher in goitrogens include broccoli, cauliflower, cabbage and bok choy.

For most people, moderate amounts seem fine. Avoiding them completely is usually unnecessary. However, if someone has low iodine intake and eats very large amounts of these foods, it may be worth looking at.

Soy

Soy is another food that often gets blamed for thyroid issues. However, a review of 14 relevant studies found soy had minimal impact on thyroid markers.

There may be some cases where soy matters more, such as subclinical or borderline hypothyroidism, low iodine intake or very high soy intake. Still, for most people, there is no need for a black-and-white approach.

Gluten

Gluten often gets discussed in Hashimoto’s, especially online. However, current research does not show that removing gluten improves symptoms unless someone has coeliac disease or possibly non-coeliac gluten sensitivity.

Coeliac disease is more common in people with Hashimoto’s, so testing can be worthwhile. Importantly, testing should happen before removing gluten, otherwise the results may not be accurate.

Dairy and Lactose Intolerance

dairy

Dairy does not appear to be something everyone with Hashimoto’s needs to avoid. However, lactose intolerance may be more common in people with Hashimoto’s.

One study found a very high rate of lactose intolerance in a small group of people with Hashimoto’s. Because of this, it may be more useful to investigate lactose intolerance rather than cutting out all dairy.

For many people, lactose-free options can make symptoms easier to manage without needing to remove dairy completely.

Vitamin D, Zinc, B12, Magnesium and Iron

Several nutrients appear to be relevant in Hashimoto’s.

Vitamin D levels are more likely to be low in people with Hashimoto’s. Vitamin D may also have a role in reducing thyroid antibodies, so checking levels and supplementing when needed may be useful.

Zinc is needed for the production of thyroid hormones and thyroid stimulating hormone. While the research is not strong enough to make bold claims, a good zinc intake still makes sense.

B12 deficiency is also more common in Hashimoto’s than in the general population. A blood test can help identify whether supplementation is needed.

Magnesium may also be worth looking at, especially because many people have suboptimal intakes. While research on magnesium and thyroid markers is limited, improving intake may help with some symptoms.

Iron deficiency is more common in Hashimoto’s too. This may partly relate to coeliac disease or reduced absorption. Since iron is needed to produce thyroid hormones, testing iron levels and supplementing when needed can be important.

Omega-3 Intake

Omega-3s may help reduce inflammation, although there is not much human research specifically linking omega-3 intake with Hashimoto’s outcomes.

Even so, having a good omega-3 intake can still support general health. If it helps from a thyroid perspective too, that is a bonus.

Digestive Symptoms and Constipation

Thyroid hormones play a role in digestion. When thyroid function is low, gut motility can slow down, which may contribute to constipation.

Helpful strategies may include increasing fibre gradually, using soluble fibre such as psyllium husk, or adding foods like kiwifruit. These are the same strategies often used for constipation, but they may become even more relevant for people with Hashimoto’s.

Weight Management With Hashimoto’s

Weight loss person on scale

Hashimoto’s can make weight management harder, especially when thyroid hormones are not well managed. A lower thyroid hormone output can reduce resting metabolic rate, and symptoms like fatigue can also make it harder to stay active.

Research suggests untreated Hashimoto’s may reduce resting metabolic rate by up to around 15%. This can make weight loss more challenging, but it does not make it impossible.

Once thyroid hormones are managed well, energy expenditure often comes close to what would be expected. From there, weight management uses the same core principles as usual, but with extra attention to symptoms, energy levels and realistic adjustments.

Gut Health

Thyroid diseases are often linked with changes in gut health, including dysbiosis. This may contribute to further inflammation.

Because of this, general gut health strategies may be useful alongside the other nutrition approaches discussed.

Key Takeaways

Hashimoto’s thyroiditis is complex, and nutrition is only one piece of the puzzle. Medical management, blood tests and symptom monitoring all matter.

From a nutrition perspective, the biggest priorities are a nutrient-rich diet, checking for deficiencies, managing constipation or gut symptoms, and avoiding unnecessary food rules.

Some nutrients, such as selenium, iodine, vitamin D, iron, B12 and zinc, can matter. However, more is not always better. The most useful approach is targeted, practical and based on the person’s actual intake, symptoms and blood results.

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