If you suspect celiac disease, speak with a healthcare professional before beginning a gluten-free diet.
Standard celiac blood tests are generally most reliable when a person is still consuming gluten.
Removing gluten beforehand can affect test results and make diagnosis more difficult.
A healthcare professional can determine whether testing is appropriate and explain the next steps.
Choosing a balanced gluten-free diet
For people who medically need to avoid gluten, suitable alternatives include:
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Rice.
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Quinoa.
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Buckwheat.
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Certified gluten-free oats.
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Potatoes.
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Corn.
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Legumes.
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Naturally gluten-free whole foods.
It is also important to avoid replacing every gluten-containing product with highly refined gluten-free snacks.
A gluten-free diet can still be low in fiber and certain nutrients if it relies heavily on packaged products.
The takeaway: Gluten is not automatically harmful to the thyroid. A gluten-free diet is essential for people with celiac disease, but routine gluten elimination is not currently recommended for everyone with hypothyroidism or Hashimoto's thyroiditis.
Other Dietary Habits That Can Interfere With Thyroid Medication
Beyond these six food categories, another important issue deserves attention: the way certain foods and supplements interact with thyroid medication.
For people taking levothyroxine, medication absorption is a major consideration.
Even a healthy food can become problematic if consumed at the wrong time.
Coffee
Coffee can reduce levothyroxine absorption when consumed too soon after taking the medication.
People taking the tablet form are generally advised to take it with water and wait approximately 30 to 60 minutes before drinking coffee or eating breakfast, according to their healthcare provider's instructions.
Calcium-rich foods and supplements
Calcium can interfere with the absorption of levothyroxine.
Calcium supplements and certain calcium-containing products may need to be separated from medication by approximately four hours.
The exact advice should follow the medication instructions and guidance from the prescribing clinician.
Iron supplements
Iron supplements can also reduce levothyroxine absorption.
People taking both medications are commonly advised to separate them by at least four hours.
This is especially important for individuals being treated for iron deficiency.
High-fiber foods
Dietary fiber is beneficial for digestive health.
However, a sudden increase in fiber consumption may affect levothyroxine absorption in some individuals.
People taking thyroid medication should maintain a reasonably consistent dietary pattern and discuss significant changes with their healthcare provider.
The solution is not to avoid fiber.
Instead, medication timing and thyroid function monitoring can help maintain stable treatment.
Seven Essential Nutrients for Supporting Thyroid Function
Although certain foods deserve attention, maintaining adequate nutrient intake is equally important.
The thyroid depends on several vitamins and minerals to function properly.
A balanced diet can help provide these nutrients without unnecessary supplementation.
1. Iodine
Iodine is essential for producing T3 and T4.
Good dietary sources include:
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Iodized salt.
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Fish.
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Dairy products.
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Eggs.
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Certain seafood.
The recommended daily iodine intake for most adults is approximately 150 micrograms.
Pregnancy and breastfeeding increase iodine requirements.
However, people with thyroid disorders should avoid taking high-dose iodine supplements unless specifically advised by a healthcare professional.
2. Selenium
Selenium supports enzymes involved in thyroid hormone metabolism and protects cells against oxidative damage.
Food sources include:
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Brazil nuts.
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Fish.
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Eggs.
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Meat.
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Whole grains.
Brazil nuts can contain extremely high and variable amounts of selenium.
Eating large quantities regularly may lead to excessive intake.
Selenium supplementation has been investigated in Hashimoto's thyroiditis, but evidence of meaningful long-term clinical benefits remains uncertain.
3. Zinc
Zinc contributes to normal immune function and several processes involved in thyroid hormone metabolism.
Sources include:
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Beef.
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Poultry.
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Shellfish.
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Pumpkin seeds.
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Beans.
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Nuts.
Severe zinc deficiency can interfere with normal physiological processes, but routine high-dose supplementation is not necessary for everyone.
4. Iron
Iron is necessary for normal thyroid hormone synthesis because it supports the activity of thyroid peroxidase.
Iron deficiency can contribute to fatigue and may complicate the symptoms experienced by someone with hypothyroidism.
Good sources include:
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Lean red meat.
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Poultry.
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Seafood.
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Lentils.
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Beans.
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Spinach.
People with suspected iron deficiency should discuss appropriate testing with their healthcare provider rather than automatically taking supplements.
5. Vitamin D
Vitamin D contributes to normal immune function and bone health.
Low vitamin D levels have been observed in some individuals with autoimmune thyroid disease.
However, this association does not prove that vitamin D deficiency directly causes Hashimoto's thyroiditis.
Sources include:
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Fatty fish.
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Egg yolks.
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Fortified dairy products.
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Fortified plant-based beverages.
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Appropriate sunlight exposure.
Supplementation may be useful when a deficiency is confirmed.
6. Vitamin B12
Vitamin B12 supports nerve function, red blood cell production, and normal cellular metabolism.
Some people with autoimmune thyroid disorders may also have conditions that affect B12 absorption.
Sources include:
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Fish.
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Meat.
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Eggs.
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Dairy products.
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Fortified foods.
People following strict vegan diets generally need a reliable source of vitamin B12 through fortified foods or supplements.
7. Protein
Protein provides amino acids needed for normal tissue maintenance and numerous biological functions.
Adequate protein intake also supports muscle health, particularly in people experiencing changes in body weight or physical activity associated with thyroid dysfunction.
Good sources include:
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Eggs.
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Fish.
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Chicken.
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Lean meat.
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Tofu.
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Beans.
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Lentils.
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Yogurt.
There is no single protein source that is universally best for thyroid health.
Dietary variety is more important.
Warning Signs That Your Thyroid May Not Be Functioning Properly
Thyroid disorders can develop gradually.
Some people experience symptoms for months before recognizing that something may be wrong.
The symptoms can also overlap with other medical conditions, making self-diagnosis unreliable.