The Ultimate Guide to What Food is Highest in Haem Iron

November 21, 2025 •

3 min read

Heme iron is significantly more bioavailable than non-heme iron, with absorption rates up to 30% compared to just 2-10% for its plant-based counterpart. This is why identifying what food is highest in haem iron is critical for individuals needing to boost their iron intake efficiently, such as those with anemia or certain dietary restrictions. This guide breaks down the most potent sources and explains why this form of iron is so vital for your health.

Quick Summary

Haem iron, predominantly found in animal products, is the most easily absorbed form of iron. The richest sources include organ meats like liver, followed by shellfish such as oysters and clams, and red meats. Incorporating these foods helps improve iron absorption and replenish body stores, supporting overall health and preventing deficiency.

Key Points

Organ Meats are Highest: Beef liver, chicken liver, and other organ meats are the most concentrated dietary sources of heme iron.
Shellfish is Potent: Oysters, clams, and mussels are exceptionally rich in highly bioavailable heme iron.
Red Meat is a Strong Source: Beef, lamb, and venison provide significant amounts of heme iron, with redder meat typically containing more.
Heme is More Absorbable: Heme iron is absorbed far more efficiently by the body than non-heme iron from plants, with absorption rates up to 35%.
Absorption Can Be Enhanced: Consuming heme iron with non-heme sources or vitamin C can improve overall iron absorption.
Targeted Need for Heme Iron: Pregnant women, those with heavy periods, and individuals with absorption issues benefit most from prioritizing heme iron.

What is Heme Iron and Why is it Better?

Dietary iron exists in two forms: heme and non-heme. Heme iron comes from animal sources, specifically from the hemoglobin and myoglobin in meat, poultry, and seafood. Non-heme iron is found in plants, eggs, and fortified foods. The key advantage of heme iron is its superior absorption rate, ranging from 15% to 35%. This is because it has a dedicated absorption pathway unaffected by many dietary inhibitors found in plant foods. Non-heme iron absorption is lower and more variable (2-10%) as it is sensitive to these inhibitors. This high bioavailability makes heme iron particularly beneficial for groups at higher risk of iron deficiency.

The Richest Sources of Heme Iron

To maximize heme iron intake, certain foods stand out.

Organ Meats: Top Tier

Organ meats are exceptionally high in heme iron. Beef liver, for instance, provides over 5 mg per 3-ounce serving. Kidney and heart are also excellent sources.

Shellfish and Seafood

Many seafood options are rich in heme iron.

Oysters: A 3-ounce serving offers around 8 mg of iron, making them one of the highest sources.
Clams and Mussels: These shellfish are also very good sources.
Sardines and Tuna: These provide valuable heme iron.

Red Meat and Poultry

Red meat is well-known for its heme iron content, which varies by cut.

Beef: Lean beef cuts are a good source, with redder meat generally having more iron.
Lamb and Venison: These are also strong sources.
Poultry: Dark meat poultry, like chicken thighs, offers a good amount of heme iron.

Comparison of Iron-Rich Foods (Heme vs. Non-Heme)

This table illustrates the difference in iron content and typical absorption between some heme and non-heme sources.


Food Source (3 oz/75g serving)	Iron Content (mg)	Type of Iron	Bioavailability (%)	Notes
Beef Liver (cooked)	~5	Heme & Non-Heme	15-35%	Very high density.
Oysters (cooked)	~8	Heme & Non-Heme	15-35%	Among highest sources.
Ground Beef (lean)	~2.5	Heme & Non-Heme	15-35%	Common source.
Spinach (1/2 cup cooked)	~3	Non-Heme	2-10%	Absorption can be inhibited.
Lentils (1/2 cup cooked)	~3	Non-Heme	2-10%	Absorption can be inhibited.
Pumpkin Seeds (1/4 cup)	~4.7	Non-Heme	2-10%	Absorption enhanced with Vitamin C.

How to Maximize Heme Iron in Your Diet

Optimizing iron intake involves selecting the right foods and considering how they are consumed.

Focus on Top Heme Sources: Regularly include organ meats and shellfish for the most efficient iron intake.
Combine Heme and Non-Heme: Eating heme iron with plant-based iron can improve non-heme iron absorption (the “meat factor”).
Include Vitamin C: Pairing iron-rich foods with vitamin C sources (like citrus or bell peppers) significantly boosts non-heme iron absorption.
Be Mindful of Inhibitors: Avoid consuming tea, coffee, or large amounts of calcium with iron-rich meals as they can hinder absorption.

Who Needs to Focus on Heme Iron?

Certain individuals benefit more from prioritizing heme iron sources due to higher requirements or absorption issues. These include:

Women: Especially those who are menstruating or pregnant, due to increased needs and blood loss.
Children: Rapid growth phases increase iron requirements.
Athletes: High-endurance activities can increase iron needs.
Individuals with absorption issues: Conditions affecting absorption make highly bioavailable heme iron important.
Frequent blood donors: Donations deplete iron stores.

Conclusion

For the highest and most bioavailable dietary iron, organ meats like liver and specific shellfish such as oysters are the best sources. Incorporating these foods effectively boosts iron levels, particularly for those at risk of deficiency. Understanding the benefits of heme iron and smart dietary combinations supports overall health. For more information, consult the National Institutes of Health's factsheet on iron.

Frequently Asked Questions

Organ meats, particularly liver (beef or chicken), are the most concentrated single food source of heme iron.

Heme iron is better absorbed because it has a specialized transport pathway in the body that is not inhibited by other foods, unlike non-heme iron from plant sources.

Yes, vegetarians can get enough iron from plant-based foods (non-heme iron), but they may need to consume almost twice as much iron due to its lower bioavailability. Combining these foods with sources of vitamin C greatly enhances absorption.

To increase iron absorption, pair iron-rich foods with foods high in vitamin C, such as citrus fruits, bell peppers, and broccoli. Additionally, incorporating animal products can enhance non-heme iron absorption through the "meat factor" effect.

Shellfish like oysters, clams, and mussels are among the richest seafood sources of heme iron.

You can increase iron levels without organ meats by consuming other heme sources like red meat and shellfish, and by boosting non-heme iron absorption from plant foods with vitamin C.

Yes, compounds called tannins in coffee and tea can inhibit iron absorption, particularly non-heme iron. It is best to avoid drinking them with or immediately after an iron-rich meal.