Hypothyroidism occurs when levels of the two thyroid hormones, triiodothyronine (T3) and thyroxine (T4), are too low. Although changing your diet alone isn’t enough to restore normal thyroid hormone levels, avoiding some foods and eating more of others can improve your body’s absorption of these hormones.

Foods to avoid

Many common foods and supplements contain compounds that interfere with thyroid function. In general, it’s best to avoid the following:

Soy

Studies suggest that phytoestrogens in soybeans and soy-rich foods may inhibit the activity of an enzyme that makes thyroid hormones. One study found that women who consumed soy supplements were three times more likely to develop hypothyroidism.

Iodine-rich foods

Some forms of hypothyroidism are caused by a lack of sufficient iodine. In such cases, using iodized salt or iodine-enriched foods can be beneficial. But eating too much iodine can have the opposite effect and suppress thyroid gland activity. Check with your doctor before taking supplements.

Iron and calcium supplements

Taking iron or calcium supplements can also change the effectiveness of many thyroid medications.

High-fiber foods

Although a high-fiber diet is usually recommended, too much fiber eaten right after taking thyroid medicines may interfere with their absorption. Wait two hours before you eat a high-fiber meal (one with more than about 15 grams of fiber).

Certain vegetables

Cruciferous vegetables that are rich in fiber, like broccoli, cabbage, spinach, kale, and Brussels sprouts, may inhibit thyroid medication absorption. Reducing the amounts of such produce in the morning right after taking your medication may help.

Caffeine, tobacco, and alcohol can also influence the effectiveness of thyroid medicine. Ask your doctor for tips on how to regulate or reduce your consumption.

Foods to eat

Nutrient-rich foods that improve your health may also benefit your thyroid gland. Certain compounds and supplements may help as well. These include:

Antioxidant-rich fruits and vegetables

Blueberries, tomatoes, bell peppers, and other foods rich in antioxidants can improve overall health and benefit the thyroid gland. Eating foods high in B vitamins, like whole grains, may also help.

Selenium

Tiny amounts of selenium are needed for the enzymes that make thyroid hormones to work properly. Eating selenium-rich foods, such as sunflower seeds or Brazil nuts, can be beneficial.

Tyrosine

This amino acid is used by the thyroid gland to produce T3 and T4. Good sources of tyrosine are meats, dairy, and legumes. Taking a supplement may help, but ask your doctor beforehand.

Diet plans and herbal supplements

Hypothyroidism doesn’t have to prevent or limit you from following a healthy lifestyle. People with hypothyroidism can choose to be vegetarian, eat protein-rich foods, and avoid ingredients that may cause an allergy.

You may also decide to use alternative medicines for hypothyroidism. Some plant extracts, like ashwagandha (Withania somnifera), coleus (Coleus forskohlii), gotu kola (Centella asiatica), and guggul (Commiphora mukul), may ease symptoms of hypothyroidism. Evidence to support these claims are limited, however. Always speak with your doctor before making any big changes to your eating habits or before taking any supplements. Having your doctor routinely check your thyroid levels can also provide insight into how your lifestyle changes are affecting your thyroid and your overall metabolism.