What Part of the Egg Has the Most Iron? A Nutritional Breakdown

January 4, 2026 •

3 min read

Did you know that the egg yolk contains the vast majority of an egg's iron content? When asking what part of the egg has the most iron, the answer is found in the vibrant, yellow center, not the transparent egg white, contrary to some common misconceptions.

Quick Summary

The egg yolk is significantly richer in iron and other vital nutrients than the egg white. While egg iron is not easily absorbed, pairing eggs with vitamin C can boost its bioavailability.

Key Points

Iron is in the Yolk: The egg yolk is the primary source of iron in an egg, containing a significantly higher concentration than the egg white.
Low Bioavailability: The iron in eggs, largely non-heme, has low bioavailability due to the presence of phosvitin in the yolk, which inhibits its absorption.
Boost Absorption with Vitamin C: Pairing eggs with vitamin C-rich foods like orange juice or bell peppers can dramatically increase the body's ability to absorb the iron.
Yolk is a Nutrient Powerhouse: Beyond iron, the yolk contains most of the egg's fat-soluble vitamins (A, D, E, K), choline, zinc, and other essential minerals.
Eat the Whole Egg: Eating the whole egg is the best way to get the full nutritional benefits and to take advantage of the synergistic effects of all its components.

Eggs are a staple in many diets around the world, prized for their protein content and versatility. But beyond the popular egg white omelet and rich, golden yolks lies a more complex nutritional story, especially concerning the mineral iron. The concentration of iron is not evenly distributed, with one part of the egg being a clear winner.

The Nutritional Roles of Egg Yolk and Egg White

To understand where the iron lies, it's helpful to look at the composition of the two main parts of an egg: the yolk and the white. The egg white, also known as the albumen, is primarily made of protein and water, making it a low-calorie, high-protein food. The yolk, however, is a powerhouse of nutrients, including fat-soluble vitamins (A, D, E, and K), essential fatty acids, and a broad spectrum of minerals.

Iron is Concentrated in the Yolk

The yolk is where almost all of an egg's iron is found, with research indicating that up to 90% of the iron resides here. In a nutritional comparison, 100 grams of raw egg yolk contains approximately 2.73 mg of iron, whereas the same amount of egg white contains a mere 0.08 mg. This vast difference makes the yolk the definitive answer to the question of which part has the most iron. The iron in eggs is present in both heme and non-heme forms, but predominantly as non-heme, which affects its absorption.

Other Nutritional Disparities

Iron isn't the only nutrient concentrated in the yolk. The nutritional density of the yolk far outweighs that of the white across many micronutrients. For instance, the yolk contains:

Vitamins A, D, E, and K
Choline, vital for brain development and cellular function
Vitamin B12 and folate
Minerals like zinc and phosphorus

Conversely, the egg white offers more protein by weight and is a better source of certain B vitamins like riboflavin (B2) and minerals such as magnesium and potassium. However, when it comes to a broad spectrum of micronutrients, the yolk is unmatched.

Bioavailability and Maximizing Iron Absorption

While the yolk contains significant iron, the story doesn't end there. The human body's ability to absorb this iron, known as bioavailability, is limited. The yolk contains a phosphoprotein called phosvitin, which binds to iron and inhibits its absorption. Studies have shown that iron absorption from eggs can be as low as 3.7%, making them a less efficient iron source than red meat, for example.

The Vitamin C Solution

The good news is that you can significantly enhance the body's ability to absorb the non-heme iron from eggs. The key is to pair eggs with a food rich in vitamin C. Vitamin C helps convert the non-heme iron into a form that is more easily absorbed by the body. A classic breakfast pairing of eggs and a glass of orange juice works perfectly, as does adding vegetables high in vitamin C, such as bell peppers or tomatoes, to a frittata or scrambled eggs.

Comparison Table: Nutrient Content per 100g of Egg


Nutrient	Whole Egg (Raw)	Egg Yolk (Raw)	Egg White (Raw)
Iron	1.75 mg	2.73 mg	0.08 mg
Calcium	56 mg	129 mg	7 mg
Phosphorus	198 mg	390 mg	15 mg
Magnesium	12 mg	5 mg	11 mg
Protein	12.6 g	15.86 g*	10.9 g*

*Note: Protein values vary slightly between sources, but the overall concentration trend remains consistent.

The Whole Egg Advantage

Although the white is low in iron, abandoning the yolk means missing out on the vast majority of the egg's micronutrients, including its rich iron content. Some studies suggest that eating the whole egg provides synergistic benefits that are not gained by eating the parts in isolation. The combination of nutrients in the whole egg makes it a powerful dietary component for overall health.

Conclusion

In conclusion, the egg yolk is the part of the egg with the most iron, containing a high concentration of this essential mineral along with a wealth of other vitamins and nutrients. While the body's ability to absorb this iron is naturally limited by a compound in the yolk, this can be improved by simply enjoying your eggs with a source of vitamin C. Eating the whole egg ensures you reap the complete nutritional benefits, making it a smart and healthy choice. Instead of worrying about isolating certain parts, focus on incorporating the complete egg into a balanced diet to support your overall well-being.

For more in-depth nutritional information, you can visit the American Egg Board website for valuable insights on egg composition and health.

Frequently Asked Questions

No, the iron in eggs has relatively low bioavailability and is not easily absorbed by the body. A protein in the yolk, called phosvitin, binds to the iron and inhibits absorption.

To increase iron absorption from eggs, you should eat them with foods high in vitamin C. Examples include pairing your eggs with a side of bell peppers, tomatoes, or a glass of orange juice.

While trace amounts of iron can be found in the egg white, it contains a negligible amount compared to the yolk. Most studies show that nearly all of an egg's iron content is in the yolk.

The yolk is more nutrient-dense and contains a wider range of vitamins and minerals, including iron, choline, and fat-soluble vitamins. However, the egg white is an excellent source of protein and is lower in calories. Both parts offer unique nutritional benefits.

Eggs contain iron, but due to low absorption rates, they are not the most effective food for combating iron-deficiency anemia on their own. They are best consumed as part of a varied diet that includes other, more bioavailable iron sources.

Cooking an egg does not significantly alter its iron content. However, how you prepare and what you pair it with can affect how much of that iron your body can absorb.

The egg yolk serves as the primary food source for a developing embryo, so it is naturally concentrated with a wide array of vitamins, minerals, fats, and other essential nutrients to support growth.