Is the Iron in Kale Easily Absorbed? Separating Fact from Fiction

January 14, 2026 •

4 min read

Non-heme iron from plant-based foods like kale is absorbed less efficiently by the body than heme iron from animal products. While kale contains this crucial mineral, a common question for many is: is the iron in kale easily absorbed, and how can you improve its uptake?

Quick Summary

Kale contains non-heme iron, which is not as readily absorbed as heme iron. Absorption can be significantly enhanced by consuming kale with vitamin C and meat, while being inhibited by certain compounds.

Key Points

Absorption is Not Easy: Kale contains non-heme iron, which is significantly less bioavailable than heme iron from animal sources.
Vitamin C is Key: Vitamin C dramatically enhances the absorption of non-heme iron, and kale's natural content is a plus; pairing with extra sources is even better.
Watch for Inhibitors: Compounds like phytates in grains and polyphenols in coffee/tea can hinder non-heme iron absorption.
Cooking Helps: Cooking kale can break down cell walls, making nutrients more accessible and potentially reducing the impact of some inhibitors.
Strategic Pairings: Combining kale with vitamin C, meat, or using a cast-iron pan are effective strategies to maximize iron absorption.

Heme vs. Non-Heme Iron: Understanding the Difference

Iron found in foods exists in two primary forms: heme and non-heme. The type of iron determines how effectively your body can absorb and utilize it.

Heme Iron: This form is found exclusively in animal-based products like red meat, poultry, and fish. It has a higher bioavailability, meaning it is more easily and efficiently absorbed by the body.
Non-Heme Iron: Found in plant-based foods such as kale, beans, lentils, nuts, and fortified grains, non-heme iron is less readily absorbed. Its absorption rate is highly influenced by other components in a meal, including both enhancers and inhibitors. Kale, therefore, contains non-heme iron, making its absorption more complex than simply ingesting it.

Factors Influencing Iron Absorption from Kale

Several dietary and preparation factors can dramatically impact how much iron your body actually absorbs from a serving of kale.

The Importance of Vitamin C

Vitamin C (ascorbic acid) is one of the most powerful promoters of non-heme iron absorption. It captures non-heme iron and converts it into a more soluble form that your body can absorb more easily. Kale is naturally rich in vitamin C, with one cup providing a significant portion of the recommended daily intake. This built-in vitamin C helps to offset some of the absorption challenges of non-heme iron. However, pairing kale with additional vitamin C-rich foods, such as citrus fruits, bell peppers, or tomatoes, can further boost absorption.

Inhibitors That Can Hinder Absorption

Even with its vitamin C content, kale's iron bioavailability is affected by natural compounds that can inhibit absorption:

Phytates: Found in whole grains, legumes, and seeds, phytates can bind to iron, making it less available for absorption. For example, a meal pairing kale with beans could have reduced iron absorption if the phytates in the beans are not mitigated.
Polyphenols: Compounds in coffee and tea, such as tannins, are known inhibitors of non-heme iron absorption. Drinking coffee or tea with your meal can significantly decrease the amount of iron you absorb from the kale.
Calcium: High doses of calcium can inhibit both heme and non-heme iron absorption, though its effect is considered minor for those with a balanced diet.
Oxalates: While raw kale contains oxalates, a compound that can bind with minerals, studies suggest their impact on iron absorption from kale is minimal.

How Cooking Affects Absorption

Your preparation method can play a role in optimizing iron bioavailability from kale. Cooking kale, for example, can break down cell walls and reduce the concentration of certain inhibitors, making the iron more accessible. Lightly steaming or sautéing kale is more effective than consuming it raw for the purpose of maximizing iron absorption.

Enhancing vs. Inhibiting Iron Absorption from Plant Foods


Category	Enhancers	Inhibitors
Micronutrients	Vitamin C, Vitamin A/Beta-Carotene	Calcium (high doses)
Foods/Compounds	Meat (for the "meat factor"), Fish, Poultry, Fermented Foods (Lactic Acid)	Phytates (in grains, legumes), Polyphenols (in coffee, tea), Oxalates (minimal effect)
Preparation	Cooking, Soaking/Sprouting (for legumes)	Raw consumption (retains more inhibitors)

Practical Tips for Maximizing Iron Absorption from Kale

To get the most out of the iron in your kale, adopt these simple dietary strategies:

Add Citrus: Squeeze lemon juice over your cooked kale salad, or add a handful of strawberries to your kale smoothie.
Pair with Protein: Combine kale with meat, fish, or poultry. The "meat factor" significantly enhances non-heme iron absorption.
Cook Your Greens: Opt for cooked kale over raw when possible to break down cell walls and reduce inhibitors like oxalates.
Time Your Beverages: Avoid drinking coffee or tea around the same time as your iron-rich meals to prevent tannins from interfering with absorption.
Cook in Cast Iron: For acidic kale dishes, cooking in a cast-iron skillet can increase the iron content of your meal.
Combine with Other Non-Heme Sources: Pair kale with legumes like lentils or chickpeas, which are also good sources of non-heme iron.

The Bottom Line: Is Iron in Kale Easily Absorbed?

In short, the iron in kale is not inherently easy to absorb. It's a non-heme source, which is less bioavailable than heme iron. However, this doesn't mean kale is a poor source of iron. By understanding the dietary factors at play, you can significantly enhance absorption.

For a complete nutritional approach, it's crucial to consider the entire meal's composition, not just the iron content of one ingredient. A well-planned, balanced diet can leverage the natural enhancers in food to make the iron from kale and other plant sources readily available for your body to use. Ultimately, a strategic approach to meal planning makes kale a valuable contributor to your overall iron intake.

For further information on nutrients and compounds affecting iron absorption, consult research reviews on the topic.

Frequently Asked Questions

Iron from kale is in the non-heme form, whereas meat contains highly bioavailable heme iron. Heme iron is absorbed more efficiently by the body than non-heme iron, whose absorption is influenced by other dietary factors.

Yes, cooking kale can improve iron absorption. It helps break down the plant's cellular structure, making the iron more accessible for your body to absorb.

To get more iron from kale, pair it with foods rich in Vitamin C, such as bell peppers, citrus fruits, or tomatoes. This significantly boosts the absorption of non-heme iron.

Yes, it is best to avoid coffee and tea at the same time as consuming kale. The polyphenols and tannins in these drinks can inhibit non-heme iron absorption.

No, studies suggest that oxalates in kale have a minor impact on iron absorption, especially compared to other inhibitors like phytates and polyphenols. The oxalates often bind with calcium, reducing their ability to interfere with iron uptake.

A single cup of cooked kale can contain approximately 2.24 mg of iron, though the exact amount can vary. It also provides a significant amount of vitamin C, which aids in absorption.

Yes, adding meat to a kale dish is very beneficial. The 'meat factor' present in animal protein enhances the absorption of non-heme iron from plant sources.