What should not be eaten with hypothyroidism

Aug 26, 2025 Source: Cainiu Health

Dr. Yang Ziqi

Introduction

Hypothyroidism generally refers to hypofunction of the thyroid gland. In general, individuals with hypothyroidism should avoid eating foods such as kelp, nori, hairtail, soybeans, and cabbage. They should also use the following medications cautiously: ferrous sulfate tablets, calcium carbonate D3 tablets, aluminum hydroxide tablets, sodium levothyroxine tablets, and amiodarone hydrochloride tablets. A detailed explanation is as follows:

　　Hypothyroidism usually refers to hypofunction of the thyroid gland. Generally, patients with hypothyroidism should avoid foods such as kelp, nori, hairtail fish, soybeans, and cabbage. They should also cautiously use medications such as ferrous sulfate tablets, calcium carbonate D3 tablets, aluminum hydroxide tablets, levothyroxine sodium tablets, and amiodarone hydrochloride tablets. Detailed explanations are as follows:

　　I. Foods

　　1. Kelp

　　Rich in iodine, kelp should be avoided because patients with hypothyroidism have reduced capacity to synthesize thyroid hormones. Excessive iodine further inhibits thyroid function, worsening the deficiency of thyroid hormone secretion and possibly exacerbating symptoms like fatigue and cold intolerance, which is detrimental to disease management.

　　2. Nori

　　Nori has extremely high iodine content. Its consumption can overload the body with iodine, interfering with the thyroid's normal utilization of iodine and affecting the synthesis and release of thyroid hormones. This may worsen various symptoms of hypothyroidism, such as drowsiness and weight gain.

　　3. Hairtail Fish

　　Hairtail fish contains a certain amount of iodine, and some varieties are high in fat. Patients with hypothyroidism experience a slower metabolic rate, and excessive fat intake can easily lead to elevated blood lipids. Additionally, iodine intake may adversely affect thyroid function, worsening the condition.

　　4. Soybeans

　　Soybeans contain substances like isoflavones, which may interfere with the synthesis and absorption of thyroid hormones. Especially in patients with hypothyroidism who already have insufficient thyroid hormone levels, these substances can further lower thyroid hormone levels in the body, affecting normal metabolic processes.

　　5. Cabbage

　　Cabbage contains thiocyanate, which may convert into goitrogenic substances in the body. These substances inhibit the thyroid's uptake and utilization of iodine, hindering the synthesis of thyroid hormones and worsening symptoms of hypothyroidism, such as goiter and fatigue.

　　II. Medications

　　1. Ferrous Sulfate Tablets

　　As an iron supplement, ferrous sulfate competes with thyroid hormone replacement drugs (e.g., levothyroxine sodium tablets) for absorption sites in the intestines, reducing the absorption efficiency of thyroid hormones. This leads to insufficient thyroid hormone levels in the body, affecting the treatment effectiveness for hypothyroidism.

　　2. Calcium Carbonate D3 Tablets

　　As a calcium supplement, calcium can bind with thyroid hormones to form insoluble complexes, reducing their absorption. This prevents thyroid hormone levels in patients with hypothyroidism from reaching effective therapeutic concentrations, which is detrimental to disease control.

　　3. Aluminum Hydroxide Tablets

　　An antacid, aluminum hydroxide forms a gel-like substance in the gastrointestinal tract that adsorbs thyroid hormones, impeding their absorption. This results in reduced effectiveness of replacement therapy for hypothyroidism, worsening symptoms such as fatigue and cold intolerance.

　　4. Levothyroxine Sodium Tablets

　　Although this is a medication for treating hypothyroidism, it must be strictly used as directed by a physician. Self-increasing the dosage can lead to excessive thyroid hormone levels in the body, causing hyperthyroidism-like symptoms such as palpitations, excessive sweating, and weight loss; insufficient dosage, on the other hand, fails to effectively improve symptoms of hypothyroidism.

　　5. Amiodarone Hydrochloride Tablets

　　An antiarrhythmic drug, amiodarone contains a large amount of iodine in its molecular structure. After administration, it can cause a sharp increase in iodine levels in the body, interfering with normal thyroid function. This may worsen hypothyroidism or induce abnormal fluctuations in thyroid function, which is highly detrimental to disease management.

　　In daily life, patients should maintain a regular routine, keep warm, and avoid excessive fatigue. If symptoms worsen or adverse drug reactions occur, prompt medical attention is required to adjust diet and medication plans under a physician's guidance.

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What should not be eaten with hypothyroidism

Hypothyroidism generally refers to hypothyroidism. Under normal circumstances, patients with hypothyroidism should avoid consuming foods such as kelp, cabbage, pork belly, pork liver, and cold watermelon, as well as medications including ferrous sulfate tablets, prednisone tablets, amiodarone tablets, amitriptyline tablets, and phenytoin sodium tablets. These foods and medications may affect thyroid hormone synthesis or drug absorption.

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9 Foods to Avoid with Hypothyroidism

In general, there is no specific list of "9 foods to avoid for hypothyroidism." However, hypothyroid patients usually need to avoid cruciferous vegetables such as cabbage, Chinese cabbage, rape, cassava, walnuts, and similar foods, as they may affect thyroid function. If there is a need to regulate overall health, it is important to plan the diet appropriately. In daily life, in addition to avoiding the aforementioned foods, patients with hypothyroidism should also maintain a balanced diet.