Evidence-based guide
Thyroid Glandand nutrition.
What to eat with hypothyroidism and Hashimoto's thyroiditis, which micronutrients are important, and where the limits of diet lie.
Materials prepared by Olga Bezugla, PhD in Medicine, clinical dietitian, former postdoctoral researcher at the German Institute of Human Nutrition (DIfE), Potsdam.
Thyroid diseases are among the most common endocrine conditions worldwide, and most patients are women.
The gland regulates metabolism, energy, body temperature, heart rate, and hormonal balance. The synthesis of its hormones depends on iodine, selenium, zinc, and iron, and autoimmune conditions — Hashimoto's thyroiditis and Graves' disease — are associated with inflammation that can be influenced by nutrition.
Key topics.
Hypothyroidism and Hashimoto's thyroiditis
The most common thyroid disorder. Nutrition supports levothyroxine treatment: selenium (reduces antibodies to TPO), anti-inflammatory diet, and caution with iodine.
Nutrition for hypothyroidismHormones and intermittent fasting
Calorie restriction affects TSH and thyroid hormones. Moderate time-restricted eating may be beneficial, while strict restrictions can suppress gland function in hypothyroidism.
Intermittent fasting and hormonesGut microbiome
Dysbiosis is linked to autoimmune thyroid diseases: iodine metabolism, T4 to T3 conversion in the gut, mucosal permeability.
Nutrition for the microbiomeWeight in hypothyroidism
Untreated hypothyroidism lowers basal metabolism and retains fluid. Even with normal TSH, metabolism may remain lower, thus requiring a personalised approach to energy balance.
Weight correctionThe endocrine system as a whole
The thyroid gland is linked to insulin resistance, adrenal glands, oestrogens, and reproductive health.
Endocrine diseasesMicronutrients for the thyroid gland.
| Nutrient | Role | Sources |
|---|---|---|
| Selenium | Needed for enzymes that convert T4 to T3; reduces TPO antibodies in Hashimoto's | Brazil nuts (1–2 per day), fish, eggs, sunflower seeds |
| Iodine | Essential for hormone synthesis; excess can worsen autoimmune thyroiditis | Seaweed (in moderation), dairy products, iodised salt, fish |
| Zinc | Supports TSH receptor sensitivity and hormone conversion | Oysters, red meat, legumes, pumpkin seeds |
| Iron | Required for thyroid peroxidase function; deficiency disrupts hormone synthesis | Red meat, legumes, fortified cereals, spinach |
| Vitamin D | Affects immunity; low levels are associated with higher TPO antibodies | Fatty fish, fortified dairy products; supplementation usually needed |
Questions.
Can diet cure hypothyroidism?
No. Hypothyroidism, especially in Hashimoto's thyroiditis, requires levothyroxine treatment if TSH is elevated. Nutrition plays a supportive role: reducing autoimmune inflammation, covering micronutrient deficiencies, and helping with metabolic consequences. But it does not replace hormone therapy.
Does everyone with Hashimoto's need a gluten-free diet?
Clear evidence exists only for those with confirmed coeliac disease or non-coeliac gluten sensitivity. For others, a Mediterranean anti-inflammatory diet is usually more practical.
Is soy harmful to the thyroid gland?
Soy isoflavones may slightly reduce levothyroxine absorption if consumed simultaneously with the medication. The solution is to take levothyroxine on an empty stomach and wait 30–60 minutes before eating. Whole soy products are not contraindicated in normal gland function or well-controlled hypothyroidism.
Personalised plan for your thyroid gland.
The doctor will review your tests, antibodies, and medications and create a plan that works alongside treatment.