What is the Difference Between Heme and Nonheme Iron?

The main difference between heme and nonheme iron lies in their sources, bioavailability, and absorption processes in the body. Here are the key differences:

1. Sources: Heme iron is found only in animal-based foods like meat, poultry, seafood, and fish, while nonheme iron is found in plant-based foods such as whole grains, nuts, seeds, legumes, and leafy greens. Nonheme iron is also present in animal products like eggs and milk/dairy.
2. Bioavailability: Heme iron is highly bioavailable, with 25-30% of it being absorbed, while nonheme iron has a lower absorption rate of 1-10%. Heme iron is better absorbed than nonheme iron, even in individuals without hemochromatosis.
3. Absorption processes: Heme iron's absorption rate is not affected by dietary factors, while nonheme iron absorption is strongly influenced by dietary factors, such as plant components like phytic acid, calcium, and polyphenols. Vitamin C and heme iron taken at the same meal can improve the absorption of nonheme iron.

In summary, heme iron is found in animal-based foods and is more easily absorbed, while nonheme iron is found in plant-based foods and has a lower absorption rate. The absorption of nonheme iron can be influenced by dietary factors, whereas heme iron's absorption is not.

Comparative Table: Heme vs Nonheme Iron

Here is a table comparing the differences between heme and non-heme iron:

In summary, heme iron is found in animal products and is more easily absorbed by the body, while non-heme iron is found in plant-based foods and has a lower absorption rate. Factors such as vitamin C, heme iron, calcium, and plant compounds can affect the absorption of both types of iron.