Foods to Avoid in Hypothyroidism
Patients with hypothyroidism should avoid soy products, as they can significantly interfere with levothyroxine absorption and may require increased medication doses to maintain euthyroid status. 1
Key Foods to Avoid or Limit
Foods That Interfere with Thyroid Medication Absorption
- Soy products: Soybeans, soy milk, tofu, and other soy-based foods can reduce levothyroxine absorption 1, 2
- Dairy products: Milk and other calcium-containing dairy products should not be consumed within 4 hours of taking levothyroxine 3
- High-fiber foods: When consumed close to medication time, these can bind to levothyroxine and reduce absorption 4
- Coffee: Espresso coffee can interfere with levothyroxine absorption 4
Timing Considerations
- Take levothyroxine on an empty stomach, 30-60 minutes before breakfast with a full glass of water 5
- Wait at least 4 hours after taking levothyroxine before consuming foods known to interfere with absorption 5
Foods Containing Goitrogens
Certain foods contain compounds called goitrogens that can interfere with thyroid hormone production, particularly in iodine-deficient individuals:
- Cruciferous vegetables when consumed raw and in large amounts:
- Broccoli
- Cauliflower
- Cabbage
- Kale
- Brussels sprouts
Note: Cooking these vegetables reduces their goitrogenic properties, making them safer for consumption by hypothyroid patients.
Foods High in Sulfites
Sulfites can trigger adverse reactions in some individuals, particularly those with both thyroid issues and asthma 6:
- Wine and beer
- Dried fruits (especially light-colored varieties)
- Processed potatoes (frozen french fries, instant mashed potatoes)
- Canned foods
- Seafood (particularly shrimp)
Iodine Considerations
- Excessive iodine: While iodine is essential for thyroid function, excessive intake can worsen autoimmune thyroiditis and lead to hypothyroidism 7
- Iodine-rich foods to consume in moderation:
- Seaweed (kelp, nori, kombu)
- Iodized salt (in excessive amounts)
Dietary Recommendations for Hypothyroid Patients
Recommended Foods
- Fresh fruits and vegetables (cooked cruciferous vegetables are fine in moderation)
- Lean proteins (chicken, turkey, fish)
- Whole grains (not consumed with medication)
- Nuts and seeds (except soy)
- Healthy fats (olive oil, avocados)
General Nutrition Guidelines
- Maintain adequate iodine intake (150 μg daily for adults) 7
- Ensure sufficient selenium intake, which supports thyroid function
- Follow a balanced diet rich in nutrients as recommended by the American Heart Association 7
Important Medication Considerations
- If you must consume soy products, separate them from levothyroxine administration by at least 4 hours 5, 2
- Monitor thyroid function regularly if dietary habits change significantly
- Be aware that certain medications (glucocorticoids, beta-blockers, amiodarone) can affect thyroid hormone conversion 5
By avoiding these problematic foods—particularly soy products and dairy when taking medication—and following proper medication timing, hypothyroid patients can optimize their thyroid function and treatment efficacy.