Which has more iron, the liver or the spleen? A Nutritional Breakdown

October 16, 2025 •

3 min read

According to nutritional data, beef spleen contains a staggering five times more bioavailable heme iron per serving than beef liver. This often-overlooked fact directly addresses the question of which has more iron, the liver or the spleen?, and underscores the immense nutritional potency of certain organ meats.

Quick Summary

Exploring the nutrient profiles of liver and spleen shows spleen as the superior source of heme iron, whereas liver provides a broader spectrum of nutrients. These co-factors found in liver can actually enhance iron absorption, making a combination of both a nutritional powerhouse for boosting iron levels.

Key Points

Spleen is an Iron Powerhouse: Beef spleen contains significantly more heme iron per serving than beef liver.
Liver is a Nutrient All-Star: While lower in iron concentration, liver is packed with vital nutrients like Vitamin A, B12, and copper, which are crucial for overall health and iron absorption.
Heme Iron is Best Absorbed: Both organs contain heme iron, which is absorbed by the body much more efficiently than the non-heme iron found in plant-based sources.
Synergy for Success: Combining liver and spleen provides both a high dose of iron and the necessary co-factors to maximize its absorption and utilization in the body.
Consider Supplements for Convenience: For those averse to the taste of organ meats, desiccated capsules containing both liver and spleen offer a simple, effective way to get the combined nutritional benefits.
Iron from Offal is Highly Bioavailable: Red meat and offal are a superior source of iron due to the high bioavailability of heme iron, making them ideal for addressing iron deficiency.

Organ meats, also known as offal, have long been prized for their dense nutritional profiles and high concentration of essential vitamins and minerals. Among these, the liver and spleen are two of the most potent sources of dietary iron, but their nutritional contributions are surprisingly different. While both offer highly absorbable heme iron, a direct comparison reveals a clear winner for overall iron concentration, though the liver's role is more complex and synergistic.

Understanding Iron Content: Spleen vs. Liver

When comparing the raw numbers, beef spleen is the undisputed heavyweight champion for iron content. In a direct head-to-head, 100 grams of beef spleen can contain as much as 45 milligrams of heme iron, while the same amount of beef liver holds around 8.3 milligrams.

This difference is rooted in the physiological function of each organ. The spleen's primary role includes filtering blood and recycling old red blood cells. Because of this function, it acts as a reservoir for iron extracted from these cells, resulting in a much higher storage concentration. The liver, while also involved in iron metabolism and storage, has many other functions, meaning its iron content, while still very high compared to muscle meat, is not as concentrated as the spleen's.

The Importance of Heme Iron

Both organs provide heme iron, the most bioavailable form of iron in the diet. Unlike the non-heme iron found in plants, which requires additional processing by the body for absorption, heme iron is absorbed more efficiently and directly. This means that the iron from liver and spleen is more readily available for use by the body to support critical functions, such as red blood cell production and oxygen transport.

The Broader Nutritional Picture: Beyond Iron

Focusing on iron alone doesn't tell the whole story. While spleen is the better pure iron source, the liver is a nutritional powerhouse that offers a wider range of synergistic nutrients.

Liver's Nutritional Riches:

Vitamin A (Retinol): Crucial for immune function, vision, and skin health.
Vitamin B12: Essential for red blood cell formation, DNA synthesis, and neurological function.
Copper: Vital for iron metabolism, as it helps convert and transport iron throughout the body.
Riboflavin (B2): Supports cellular growth and energy production.
Folate (B9): Important for cell growth and DNA formation.

Spleen's Unique Contributions:

Spleen-Specific Peptides: Contains peptides like splenin and tuftsin, which are thought to stimulate macrophages and enhance immune activity.

Combining Liver and Spleen for Maximum Benefit

For those seeking the most comprehensive nutritional support, a combination of both liver and spleen offers a powerful synergy. The extremely high concentration of heme iron from the spleen can be effectively utilized by the body, with the liver providing the necessary co-factors like Vitamin A, B12, and Copper to maximize absorption and overall iron status. Many health supplements now combine these two organ meats for exactly this reason, providing a complete nutritional package.

Practical Dietary Considerations

Incorporating these organ meats into your diet doesn't have to be daunting. They can be enjoyed in various forms, from fresh preparations to convenient desiccated capsules.

Fresh: Spleen can be used in dishes like sausages or slow-cooked stews, while liver is a classic ingredient in pâtés or lightly fried preparations.
Capsules: For those sensitive to the taste or smell of fresh offal, desiccated organ meat capsules offer a flavorless, accessible way to gain the benefits.

Iron and Nutrient Comparison: Liver vs. Spleen


Nutrient	Beef Liver (per 100g)	Beef Spleen (per 100g)
Heme Iron	~8.3 mg	~45 mg
Bioavailability	High (Heme Iron)	Highest (Heme Iron)
Vitamin A (Retinol)	Very High	Absent
Vitamin B12	Very High	High
Copper	Very High	Trace amounts
Spleen-Specific Peptides	Absent	Present
Synergistic Co-factors	Abundant	Limited

Conclusion

In the final analysis, the answer to which has more iron, the liver or the spleen? is clear: the spleen contains a far higher concentration of heme iron. However, for a complete nutritional approach to supporting iron levels, the liver's role is indispensable. Its rich supply of co-factors like Vitamin A, B12, and copper helps the body effectively utilize the iron from the spleen. For many, the ideal solution isn't choosing one over the other but combining them for a powerful and synergistic effect, whether through fresh food or supplement form. Organ meats truly are a nutritional superfood, offering dense, bioavailable nutrients unmatched by most other dietary sources. For further reading, an excellent resource on the nutritional value of organ meats can be found at the National Institutes of Health.

Frequently Asked Questions

For iron concentration alone, yes, spleen is a much better source, containing a significantly higher amount of heme iron per serving than liver.

Yes, liver is rich in essential co-factors like Vitamin A, B12, and copper, which play vital roles in the body's metabolism and utilization of iron.

Yes, heme iron from animal sources like organ meats is absorbed much more efficiently by the body (15% to 35%) compared to non-heme iron from plants (2% to 10%).

Combining liver and spleen creates a synergistic effect, providing the high concentration of iron from the spleen along with the broad spectrum of vitamins and minerals from the liver that enhance iron absorption.

While supplements can provide iron, the heme iron found in organ meats is naturally occurring and highly bioavailable. Supplements often mimic less-absorbable non-heme iron, and whole-food sources provide a complete nutritional profile.

Spleen has a mild flavor and can be incorporated into ground meat preparations, sausages, or slow-cooked stews. Many prefer desiccated capsules to fresh spleen due to its strong taste and texture.

Individuals on vegetarian or vegan diets may be at a higher risk of low iron levels due to consuming only non-heme iron, which is less efficiently absorbed. They must consume plenty of non-heme iron sources and pair them with Vitamin C to improve absorption.