Hypothyroidism, or underactive thyroid, occurs when the thyroid gland doesn't produce enough hormones. These hormones help your organs function and affect your energy, heart, digestion, bone strength, and more.

Without treatment, hypothyroidism can cause symptoms such as fatigue, trouble tolerating the cold, weight gain, menstruation changes, and heart symptoms. Treating hypothyroidism typically involves taking medication that helps increase thyroid hormone levels, but a well-balanced diet is also important.

Although changing your diet won't cure hypothyroidism, you may find that eating foods that benefit thyroid health -- and avoiding those that don't -- can be helpful in relieving some of your symptoms.

People with hypothyroidism may benefit from eating foods that provide certain nutrients. While research is sometimes limited and mixed, some research has suggested that the following foods may help with thyroid gland function:

Iodine stimulates the production of thyroid hormone. When the body doesn't have enough iodine, it produces less thyroid hormone than needed, which may lead to hypothyroidism. The thyroid also works harder to normalize hormone levels. An overworked thyroid can enlarge over time, leading to a condition called goiter.

Too much iodine can also cause goiter and hypothyroidism, so it's important to get the right amount. The recommended daily intake of iodine for most adults is 150 micrograms. This recommendation increases to 220 micrograms for people who are pregnant and 290 micrograms for people who are lactating.

Foods that are the best sources of iodine include:

Selenium deficiency is associated with hypothyroidism. Because of this, some researchers have hypothesized that increasing selenium intake may help ease symptoms.

Selenium may improve thyroid health by reducing antibodies that attack the thyroid gland in autoimmune-related thyroid disease. However, studies also showed no difference in levels of thyroid-stimulating hormone (TSH), which helps control thyroid hormone production. Results from studies of selenium's effects on thyroid health are mixed overall, and more evidence is needed.

The daily recommended intake of selenium is 55 micrograms for the average adult, 60 micrograms if you're pregnant, and 70 micrograms if you're lactating.

Some sources of selenium, like Brazil nuts, can offer significantly more selenium than recommended in a single serving, so it's important to be mindful of this. While getting enough selenium may be helpful, getting too much may cause hair loss, skin rash, nausea, diarrhea, and nervous system disorders.

Foods that contain selenium include:

People with hypothyroidism tend to have significantly lower levels of vitamins B12 and D. These nutrients are essential for energy metabolism, nervous system health, and bone health, all of which can be affected by low thyroid hormone levels.

Eating foods high in vitamins B12 and D may help prevent nutrient deficiencies that contribute to symptoms. Vitamin B12-rich foods include beef liver, seafood, turkey, nutritional yeast, eggs, and dairy products. Vitamin D-rich foods include cod liver oil, seafood, dairy products, and mushrooms.

Many people have hypothyroidism because of Hashimoto's disease, which occurs when the immune system mistakenly attacks and damages the thyroid gland, creating inflammation in the body.

Antioxidants can prevent or delay cell damage, and antioxidants found in some foods may help reduce inflammation. There are many antioxidant molecules, some of which are vitamins and minerals. These include vitamins A, C, and E and zinc. Foods that can be a source of antioxidants include:

There's no food or food group that all people with hypothyroidism need to avoid. However, many people have hypothyroidism due to Hashimoto's disease. With the high inflammation in the body from Hashimoto's disease, immune cells become activated, which can cause further damage.

If you have food intolerances, such as gluten or lactose, it may be beneficial to limit those foods to avoid additional inflammation. Be sure to consult your healthcare provider before making any changes.

It's a common belief that cruciferous vegetables -- which include cauliflower, broccoli, cabbage, Brussels sprouts, arugula, kale, bok choy, and turnips -- can cause or worsen hypothyroidism. These vegetables contain molecules called goitrogens that can affect thyroid function.

This belief likely stems from early research on animals suggesting that goitrogens prevent iodine absorption, as well as an older case study showing severe low thyroid symptoms after a woman ate lots of bok choy.

However, this research is outdated and limited. A more recent clinical study investigated the effects of cruciferous vegetables on thyroid hormone levels. This study showed no difference in people's thyroid hormone levels after drinking a broccoli sprout beverage for 12 weeks. Considering these results, little evidence suggests that you should avoid cruciferous vegetables.

If you aren't sure what to eat, here are some meal examples for someone with hypothyroidism:

Sweet, savory, and nutritious breakfast ideas could include:

Not skipping lunch can help you maintain energy levels and meet nutrient intake goals. Here are some options:

Here are healthy meals to enjoy for dinner as part of a balanced hypothyroidism diet:

If you have hypothyroidism, it's important to consume a well-balanced diet consisting of whole grains, lean meat, dairy products, vegetables, fruits, nuts, and seeds.

Some vitamins and minerals may be particularly helpful in managing symptoms, including iodine, selenium, vitamin B12, vitamin D, and antioxidants.