What is the highest food in iron? A definitive guide to iron-rich foods

November 15, 2025 •

3 min read

Globally, iron deficiency is the most common nutritional disorder, affecting billions of people. For many, the first step to combating this is through diet, which brings up the crucial question: what is the highest food in iron? The answer lies in both animal and plant-based sources, but the type of iron and its absorption are key.

Quick Summary

The foods highest in iron include fortified breakfast cereals, organ meats like liver, and certain seafood such as oysters. The best sources depend on whether you consume animal products and how your body absorbs different types of iron. Dietary combinations can significantly impact total iron intake.

Key Points

Fortified cereals are often the highest: A single serving of 100% fortified breakfast cereal typically contains the most iron per serving, offering 18mg.
Heme iron is better absorbed: Animal-based sources like liver, oysters, and beef contain heme iron, which is absorbed more easily by the body than non-heme iron from plants.
Oysters and liver are top natural sources: Eastern oysters and beef liver are among the most iron-dense natural foods, providing 8mg and 5mg per serving, respectively.
Plant-based sources are powerful with a boost: Legumes (lentils, white beans), seeds (pumpkin, sesame), and leafy greens (spinach) offer significant non-heme iron, but absorption is improved when eaten with vitamin C.
Dietary combinations matter for absorption: To maximize non-heme iron absorption, pair plant-based sources with foods high in vitamin C and avoid consuming them with calcium, tea, or coffee.

Understanding the Two Types of Dietary Iron

When evaluating sources of iron, it's essential to distinguish between the two types found in food: heme and non-heme iron. Heme iron comes from animal products and is more readily absorbed by the body. Non-heme iron is found in plant-based foods and fortified products and is not absorbed as efficiently. A balanced diet often includes both types, but understanding their differences can help you maximize your intake.

The Contenders for Highest Iron Content

While many foods contain iron, some stand out for their exceptional concentration. The specific highest food in iron can vary depending on the serving size and type of food, but certain categories consistently top the charts.

Heme Iron Champions

Animal-based sources offer highly bioavailable heme iron. This means your body absorbs a greater percentage of the iron from these foods compared to plant-based options.

Fortified Breakfast Cereals: While non-heme, these are often the single highest source of iron per serving due to fortification. The NIH lists a single serving of 100% fortified breakfast cereal with 18mg of iron.
Organ Meats: Liver, in particular, is a nutritional powerhouse. A 3.5-ounce (100-gram) serving of beef liver contains 6.5 mg of iron, accounting for a significant portion of the daily value.
Shellfish: Clams, oysters, and mussels are exceptionally rich in heme iron. A 3-ounce serving of cooked eastern oysters provides an impressive 8mg of iron.
Red Meat: Lean red meat, like beef, is a robust source of heme iron. A 3.5-ounce serving of ground beef offers 2.7 mg of iron.

Non-Heme Iron Powerhouses

For vegetarians and those seeking plant-based sources, several foods are packed with non-heme iron. Combining these with vitamin C-rich foods is crucial for maximizing absorption.

Legumes: Lentils, white beans, and chickpeas are excellent sources. One cup of cooked lentils provides about 6.6 mg of iron.
Spinach: A classic iron-rich green, half a cup of boiled spinach offers around 3mg of iron.
Seeds: Pumpkin, sesame, and flaxseeds are nutrient-dense and high in iron. Pumpkin seeds contain a considerable amount per serving.
Dark Chocolate: A delicious source, one ounce of dark chocolate (45–69% cacao solids) can provide around 2 mg of iron.

Maximizing Iron Absorption

Simply eating iron-rich foods isn't enough; how you combine them matters. To boost your body's ability to absorb non-heme iron, incorporate foods high in vitamin C, such as citrus fruits, bell peppers, broccoli, and tomatoes. Conversely, certain compounds can inhibit absorption. It is best to avoid consuming coffee, tea, or milk around the same time as high-iron meals. Cooking with a cast-iron skillet can also transfer small amounts of iron to your food, contributing to your overall intake.

A Comparison of Top Iron Sources


Food Source	Type of Iron	Serving Size	Iron Content (approximate)	Key Benefits
Fortified Cereal	Non-Heme	1 serving (100% DV)	18 mg	Convenient, widely available
Eastern Oysters	Heme	3 oz cooked	8 mg	High bioavailability, rich in other minerals
Beef Liver	Heme	3 oz pan-fried	5 mg	High in B vitamins, Vitamin A
Lentils	Non-Heme	1 cup cooked	6.6 mg	High in fiber, folate, plant-based
White Beans	Non-Heme	1 cup canned	8 mg	Excellent source of protein and fiber
Spinach	Non-Heme	1 cup cooked	5.7 mg	Rich in antioxidants, low calorie
Pumpkin Seeds	Non-Heme	1 cup dried	11.4 mg	Good source of healthy fats, magnesium

The Role of Iron in Your Body

Iron is an essential mineral vital for numerous bodily functions. Its primary role is in creating hemoglobin, the protein in red blood cells that carries oxygen from the lungs to all parts of the body. It also plays a part in muscle oxygenation through myoglobin and in the synthesis of certain hormones. Adequate iron is critical for maintaining energy levels, supporting cognitive function, and bolstering the immune system. Iron deficiency, if left untreated, can lead to anemia, causing fatigue, weakness, and other symptoms.

Conclusion: Your Highest Iron Food Choice

While fortified cereals often provide the single largest dose of iron per serving, the title for the most bioavailable source goes to certain shellfish and organ meats. The best choice for you depends on your dietary preferences and health goals. For omnivores, incorporating organ meats and shellfish offers highly absorbable heme iron. For vegetarians and vegans, focusing on legumes, leafy greens, and seeds, paired with vitamin C, is the most effective strategy. By building meals around these dense sources, you can ensure adequate iron intake and support your overall health. For further reading, consult the NIH Office of Dietary Supplements factsheet on iron.

Frequently Asked Questions

For vegetarians, some of the highest iron foods include lentils, white beans, spinach, and pumpkin seeds. Legumes are particularly rich sources, with a cup of cooked lentils providing a high amount of non-heme iron.

To increase iron absorption, consume non-heme iron sources (from plants) with foods rich in vitamin C, such as citrus fruits, bell peppers, and strawberries. Cooking in a cast-iron skillet can also help add iron to your meals.

Animal foods with the most iron include organ meats like beef liver, and shellfish such as oysters and clams. These are rich in heme iron, which is the most easily absorbed type.

Yes, dark chocolate can be a decent source of non-heme iron. For example, one ounce of dark chocolate with 45–69% cacao solids contains about 2mg of iron.

In many cases, yes. Fortified breakfast cereals are often engineered to contain 100% of the Daily Value for iron in a single serving, which can be a higher numerical amount than a typical serving of meat.

Certain substances can inhibit iron absorption, including tannins found in tea and coffee, and calcium found in dairy products and supplements. It is best to avoid these around the time you consume iron-rich meals.

Heme iron is found exclusively in animal products and is highly bioavailable, meaning the body absorbs it efficiently. Non-heme iron is found in plants and fortified foods and is less easily absorbed.