Which seafood is a rich source of iron?

December 6, 2025 •

3 min read

According to the National Institutes of Health, iron is one of the world's most common nutrient deficiencies, affecting over 2 billion people globally. Discover which seafood is a rich source of iron and why it's such an excellent dietary addition for boosting your iron levels effectively.

Quick Summary

Shellfish like oysters, clams, and mussels are exceptionally rich sources of heme iron, which the body absorbs more easily than plant-based iron. Fatty fish such as sardines and canned tuna also offer notable iron content. The article explores top seafood options, their benefits, and how to prepare them to maximize absorption.

Key Points

Shellfish is the Best Seafood Source of Iron: Oysters, clams, and mussels are particularly rich in highly absorbable heme iron, making them top choices for boosting iron intake.
Heme Iron Absorbs Better: The heme iron in seafood is more bioavailable than the non-heme iron in plants, meaning your body can utilize it more efficiently.
Cook to Avoid Risk: For people with hemochromatosis or to prevent bacterial infections like Vibrio vulnificus, always cook shellfish thoroughly.
Other Iron-Rich Fish Options: Besides shellfish, sardines and canned tuna offer good amounts of iron in convenient forms.
Combine with Vitamin C: To enhance iron absorption, especially from non-heme sources found alongside heme iron, pair seafood with vitamin C-rich foods like lemon juice or bell peppers.
Omega-3 Benefits: Many iron-rich seafoods, especially oily fish like sardines, also provide heart-healthy omega-3 fatty acids.
Portion Control is Important: Even for healthy individuals, monitoring intake is wise, particularly for those sensitive to high iron levels or mercury.

Why Seafood is an Excellent Source of Iron

Seafood provides a highly bioavailable form of iron known as heme iron, which is absorbed by the body far more efficiently than the non-heme iron found in plant-based sources. This makes seafood, particularly shellfish, a powerful tool for combating iron deficiency and related symptoms like fatigue and weakness. The superior absorption rate of heme iron is a key reason why animal proteins are so effective at raising iron levels.

Top Seafood Choices Rich in Iron

While many fish contain iron, shellfish consistently top the charts for iron density. Here are some of the best options:

Oysters: These briny bivalves are a standout source of iron. Depending on the type and preparation, a 3-ounce serving of oysters can provide a significant portion of the daily recommended intake. They also offer abundant zinc and vitamin B12.
Clams: Clams are another excellent shellfish for boosting iron levels. Certain canned varieties can contain very high amounts of iron, though content can vary widely by brand and processing.
Mussels: Smaller but still mighty, mussels are another iron-rich bivalve. A 3-ounce serving of cooked mussels offers a notable amount of this essential mineral. They are also a great source of protein and omega-3 fatty acids.
Sardines: These small, oily fish are surprisingly rich in iron and other nutrients. A standard serving of canned sardines provides a good amount of highly absorbable heme iron.
Canned Tuna: For a convenient and affordable option, canned tuna is a solid choice. A 3-ounce serving provides a modest yet valuable contribution to your daily iron needs.

Health Benefits of Iron-Rich Seafood

Beyond their excellent iron content, these seafood options provide a wealth of other nutritional benefits:

Protein: Seafood is a high-quality source of lean protein, essential for muscle repair, growth, and overall satiety.
Omega-3 Fatty Acids: Many fish, especially oily types like salmon, sardines, and mackerel, are packed with omega-3 fatty acids. These healthy fats are known to support brain health, reduce inflammation, and improve cardiovascular function.
Vitamins and Minerals: Iron-rich seafood is also a source of other vital nutrients, including vitamin B12, vitamin A, selenium, and zinc.

Tips for Maximizing Iron Absorption

Cooking and pairing your seafood correctly can further enhance its iron absorption. The presence of vitamin C is particularly effective at increasing the absorption of non-heme iron, and while seafood provides heme iron, vitamin C can still boost overall nutrient uptake.

To get the most out of your meal, consider these pairings:

Add a squeeze of lemon juice: The vitamin C in lemon or other citrus fruits can help your body absorb iron.
Include vitamin C-rich vegetables: Cook your seafood alongside vegetables such as bell peppers, spinach, or broccoli.
Be mindful of inhibitors: While not as big a concern with heme iron, tannins in coffee and tea can inhibit iron absorption. Avoid consuming these beverages with your meal to be extra cautious.

Comparison of Iron Content in Popular Seafood (per 100g serving)


Seafood Type	Iron (mg)	Notes
Oysters	8.26	Excellent source; check mercury levels.
Mussels	7.08	Very good source; versatile and affordable.
Clams	2.91-29.45	Content varies widely; canned baby clams can be exceptionally high.
Sardines (canned)	2.5-4+	Convenient, shelf-stable source.
Octopus	9.5	Highest documented iron content per 100g.
Canned Tuna	1.0-1.4	Convenient, moderate source.
Salmon	0.4-1.28	Lower iron content, but high in Omega-3s.

Potential Health Risks and Considerations

While beneficial, there are important considerations for certain individuals. People with hemochromatosis, a condition causing iron overload, must avoid high-iron seafood like oysters and clams. Raw shellfish consumption also carries risks for these individuals, as they are more susceptible to infections from bacteria like Vibrio vulnificus. Always cook shellfish thoroughly to eliminate this risk. Pregnant women and young children should also be mindful of mercury levels in certain fish. The FDA and EPA provide guidance on safe fish choices for these groups.

Conclusion

For those looking to increase their iron intake, seafood offers a variety of delicious and nutrient-dense options. Shellfish such as oysters, clams, and mussels provide some of the highest and most easily absorbed heme iron. Fish like sardines and tuna are also excellent additions to an iron-rich diet, offering additional benefits like omega-3 fatty acids. By incorporating a variety of these foods and following preparation tips for optimal absorption, you can effectively boost your iron levels while enjoying a flavorful and healthy diet.

This content is for informational purposes only and is not intended as medical advice. Always consult with a healthcare professional or registered dietitian for personalized dietary recommendations.

Frequently Asked Questions

Oysters and clams consistently have the highest iron content among common seafood varieties. For example, some canned baby clams can contain very high levels of iron, and a 3-ounce serving of cooked oysters offers a significant amount.

The iron found in seafood is primarily heme iron, which is absorbed more easily and efficiently by the body compared to the non-heme iron found in plant-based foods like vegetables. While both are important, heme iron is more effective at raising iron levels.

No, people with hemochromatosis, a condition causing iron overload, should generally avoid high-iron seafood like oysters and clams. They should consult a doctor or dietitian for a safe dietary plan.

Raw shellfish can carry bacteria, such as Vibrio vulnificus. People with iron overload conditions like hemochromatosis are more susceptible to severe and potentially fatal infections from this bacterium. Always cook shellfish thoroughly to eliminate this risk.

To maximize iron absorption, pair your seafood with foods rich in vitamin C, such as a squeeze of lemon juice, bell peppers, or tomatoes. The vitamin C helps the body absorb more iron, particularly the non-heme iron present.

Yes, canned fish like sardines and tuna are good sources of iron. The canning process preserves the nutrient content, making them a convenient way to get a solid dose of iron, especially for a quick meal.

No, iron content varies significantly across different types of seafood. Shellfish, such as clams, oysters, and mussels, are generally much richer in iron than many fin fish like salmon or cod.