How much iron is in an egg yolk?

December 17, 2025 •

3 min read

One large egg yolk contains a modest but notable amount of iron, typically around 0.46 to 0.5 milligrams. While eggs are a nutritious dietary staple, the iron content in an egg yolk is of the non-heme variety, which is not as easily absorbed by the human body compared to the heme iron found in meat. The presence of a protein called phosvitin further reduces its bioavailability.

Quick Summary

An average large egg yolk provides a small amount of non-heme iron, approximately 0.5mg, with limited bioavailability. A specific protein within the yolk hinders efficient absorption, but consumption alongside foods rich in vitamin C can help increase its uptake.

Key Points

Iron Amount: A large egg yolk provides approximately 0.5 mg of iron.
Iron Type: The iron found in egg yolks is non-heme, which is less efficiently absorbed by the body compared to heme iron from meat.
Low Bioavailability: The protein phosvitin in the yolk binds to iron, limiting its absorption.
Improve Absorption: Pair eggs with vitamin C-rich foods like bell peppers or citrus fruits to enhance iron uptake.
Complete Meal: For better iron status, combine eggs with other iron sources rather than relying on them alone.
Nutrient Dense: Beyond iron, egg yolks are also rich in other essential nutrients like choline, vitamin D, and B12.

The Exact Iron Content in an Egg Yolk

For those curious about the specific micronutrient contributions of their breakfast, understanding how much iron is in an egg yolk is key. Based on data from the U.S. Department of Agriculture (USDA), one large egg yolk (approx. 17g) contains roughly 0.46 to 0.5 mg of iron. This is a modest amount when considering the Recommended Dietary Allowance (RDA) for iron, which can range from 8 mg for adult men and postmenopausal women to 18 mg for premenopausal women. While the iron is concentrated almost exclusively in the yolk—with only trace amounts found in the egg white—it's important to recognize that an egg is not considered a high-iron food source on its own.

The Problem with Non-Heme Iron Bioavailability

Eggs are an animal product, but they do not provide the highly absorbable heme iron characteristic of meat, fish, and poultry. Instead, the iron found in eggs is non-heme iron, which the body absorbs far less efficiently. This lower absorption rate is primarily due to a protein found in the yolk called phosvitin. Phosvitin binds tightly to the iron, making it difficult for the body's digestive enzymes to break down and release the iron for absorption. This is why eating a whole egg has been shown to reduce dietary iron absorption in some studies. The average absorption rate for iron from eggs is quite low, estimated at around 3.7%.

Strategies for Enhancing Iron Absorption from Eggs

Despite the challenges with absorption, there are simple culinary tricks to improve the bioavailability of iron from egg yolks. The most effective method is to combine eggs with a food rich in vitamin C, which helps convert non-heme iron into a more easily absorbed form.

Foods to pair with eggs for better iron absorption:

Citrus Fruits: A side of orange or a glass of orange juice. Vitamin C is highly effective at increasing iron uptake.
Bell Peppers: Sliced bell peppers added to an omelet or scramble. They are an excellent source of vitamin C.
Tomatoes: Cooking eggs with tomatoes or serving them with salsa can boost absorption.
Dark Green Leafy Vegetables: Spinach or kale incorporated into an egg dish, though spinach also contains oxalates that can inhibit absorption. The high vitamin C content helps counteract this.
Strawberries: A serving of strawberries alongside your egg dish provides a vitamin C boost.

Comparison: Egg Yolk vs. Whole Egg Iron and Absorption


Feature	Egg Yolk (from 1 Large Egg)	Whole Egg (1 Large)
Iron Content	~0.46–0.5 mg	~0.9 mg
Iron Distribution	Almost entirely in the yolk	All iron is present, concentrated in the yolk
Type of Iron	Non-heme iron	Non-heme iron
Bioavailability	Low, due to phosvitin	Low, with components in the egg white potentially inhibiting absorption further
Best with Vitamin C?	Yes, absolutely.	Yes, to improve non-heme iron uptake.

The Bigger Picture: Iron Needs and Dietary Context

For individuals with iron deficiency or anemia, relying solely on eggs is not an effective strategy. As a nutritious, complete protein source, eggs offer many benefits beyond iron, including choline, vitamin D, and vitamin B12. A balanced diet that incorporates a variety of iron sources is the most prudent approach. Combining non-heme iron foods like eggs with heme iron sources (e.g., a breakfast sausage) can also improve overall absorption. While the iron in an egg yolk is not a powerhouse, understanding its nuances allows for more informed and effective dietary choices. For more on optimizing nutrient intake, consult resources from recognized health organizations. For instance, the National Institutes of Health provides comprehensive information on iron and other dietary nutrients.

Conclusion

In summary, one large egg yolk contains about 0.5 milligrams of non-heme iron. The iron is not highly bioavailable due to the presence of the protein phosvitin. However, consuming eggs with vitamin C-rich foods significantly boosts absorption. While eggs are a nutritious part of a balanced diet, they are a modest iron source and should not be the sole focus for correcting iron deficiency. Strategic food pairings can help you get the most out of their iron content and contribute to a healthier overall diet.

Frequently Asked Questions

Eggs are a modest source of iron, not a high one. The iron in an egg yolk is non-heme and has low bioavailability, meaning your body does not absorb it very efficiently compared to other iron sources like meat.

The iron in an egg yolk is non-heme iron. Non-heme iron is also found in plant-based foods, and its absorption is influenced by other dietary factors.

Iron from egg yolk is not easily absorbed because of a protein called phosvitin. This protein binds to the iron, preventing it from being properly released and absorbed by the body.

Heme iron is found in animal proteins like meat, poultry, and fish and is easily absorbed. Non-heme iron, found in eggs and plants, is not absorbed as efficiently.

Pair your eggs with foods high in vitamin C, which significantly enhances non-heme iron absorption. Examples include bell peppers, oranges, tomatoes, and strawberries.

There are only trace amounts of iron in egg whites. The vast majority of the iron in an egg is found in the yolk.

Cooking does not significantly alter the amount of iron in an egg yolk or its bioavailability. The iron remains non-heme and is still bound by the phosvitin protein.