✪ Key Takeaway: Cod is good for hypothyroidism because it provides selenium, iodine, and omega-3s that support thyroid hormone production.
Introduction
Your doctor just told you that you have hypothyroidism and now you are wondering what foods can help.
You have heard that fish is healthy, but you are not sure if cod specifically supports your thyroid or makes things worse.
Hi, I am Abdur, your nutrition coach and today I am going to explain exactly how cod fish affects your thyroid health and whether you should include it in your diet.
What Nutrients in Cod Support Thyroid Function?
Cod contains selenium, which is one of the most important minerals for thyroid hormone conversion.
Your thyroid produces mostly T4 hormone, but your body needs to convert it into T3, the active form that actually does the work.
Selenium-dependent enzymes called deiodinases perform this conversion process in your liver and other tissues.
A 100-gram serving of cod provides about 40 micrograms of selenium, which is roughly 73 percent of your daily requirement.
Cod also contains iodine, the building block your thyroid uses to make hormones in the first place.
The same serving gives you approximately 110 micrograms of iodine, covering about 73 percent of your daily needs.
Without enough iodine, your thyroid cannot produce adequate amounts of T4 and T3, which leads to hypothyroid symptoms like fatigue and weight gain.
✪ Fact: Selenium deficiency can reduce thyroid hormone production by up to 40 percent, even when iodine intake is adequate.
How Do Omega-3 Fatty Acids in Cod Help Your Thyroid?
Cod provides omega-3 fatty acids, specifically EPA and DHA, which reduce inflammation throughout your body.
Chronic inflammation can interfere with thyroid hormone receptors on your cells, making it harder for T3 to do its job.
When inflammation is high, your cells become less responsive to thyroid hormones, which means you experience hypothyroid symptoms even if your blood tests look normal.
Omega-3s from cod help calm this inflammatory response and improve cellular sensitivity to thyroid hormones.
These fatty acids also support the health of cell membranes, which is important because thyroid hormones need to pass through these membranes to enter cells.
A 100-gram serving of cod contains about 0.2 grams of omega-3s, which is modest compared to fatty fish like salmon but still beneficial.
Research published in the journal Thyroid shows that omega-3 supplementation can improve thyroid function markers in people with autoimmune thyroid conditions.
✪ Pro Tip: Pair cod with a handful of walnuts or ground flaxseeds to boost your total omega-3 intake for better thyroid support.
Does Cod Contain Any Nutrients That Harm Thyroid Health?
Cod itself does not contain any nutrients that directly harm your thyroid when consumed in normal amounts.
However, you need to be careful about mercury contamination, which can affect thyroid function over time.
The good news is that cod is a low-mercury fish, making it one of the safer seafood choices for regular consumption.
According to the Environmental Protection Agency, cod contains less than 0.1 parts per million of mercury, which is well below the safety threshold.
Some people with Hashimoto thyroiditis, an autoimmune form of hypothyroidism, worry about iodine making their condition worse.
While excessive iodine supplementation can trigger autoimmune flares, getting iodine from food sources like cod is generally safe and necessary.
Your body regulates iodine from food more effectively than from supplements, reducing the risk of overconsumption.
✪ Note: If you have Hashimoto thyroiditis, avoid high-dose iodine supplements but continue eating iodine-rich foods like cod in moderation.
How Much Cod Should You Eat for Thyroid Support?
Eating cod two to three times per week provides enough selenium and iodine to support healthy thyroid function.
A typical serving size is about 100 to 150 grams, which is roughly the size of your palm.
This frequency gives you consistent nutrient intake without risking overconsumption of any single mineral.
You do not need to eat cod every single day because your body stores selenium and can use it over several days.
Rotating cod with other selenium-rich foods like Brazil nuts, eggs, and chicken creates a more balanced approach.
If you are taking thyroid medication, eating cod will not interfere with your treatment as long as you maintain consistent timing.
Always take your thyroid medication on an empty stomach and wait at least 30 to 60 minutes before eating any food, including cod.
✪ Pro Tip: Bake or steam cod instead of frying to preserve its selenium content and avoid adding inflammatory oils to your meal.
What Other Foods Should You Pair With Cod?
Pairing cod with vitamin D-rich foods or getting sunlight exposure enhances thyroid hormone production.
Vitamin D receptors exist on thyroid cells, and adequate vitamin D levels improve the efficiency of thyroid hormone synthesis.
Adding vegetables like spinach, kale, or broccoli to your cod meal provides additional nutrients without interfering with thyroid function.
Some people worry that cruciferous vegetables are goitrogenic, meaning they can interfere with iodine uptake.
However, cooking these vegetables deactivates most goitrogens, and eating them with iodine-rich cod neutralizes any potential negative effect.
Including a source of healthy fat like olive oil or avocado helps your body absorb fat-soluble nutrients from your meal.
A balanced plate with cod, cooked vegetables, and a complex carbohydrate like sweet potato or quinoa supports stable blood sugar and thyroid health.
✪ Fact: Cooking cruciferous vegetables for just three minutes reduces their goitrogenic compounds by more than 90 percent.
The Bottom Line
Cod is genuinely good for hypothyroidism because it delivers selenium, iodine, and omega-3s that your thyroid needs to function properly.
Your thyroid health depends more on consistent, smart food choices than on any single miracle ingredient, and cod fits perfectly into that strategy.
I would love to hear your thoughts on this topic, so please share your questions or experiences with cod and thyroid health in the comments below.
References
At NutritionCrown, we use quality and credible sources to ensure our content is accurate and trustworthy. Below are the sources referenced in writing this article:
- PMC: Selenium and the Thyroid
- Mary Ann Liebert: Iodine Status and Thyroid Function
- Cleveland Clinic: Hypothyroidism Diet
- CommonSpirit Health: 5 Foods to Improve Thyroid Function
