Is Kale Very High in Iron? Understanding Its Nutritional Value

November 26, 2025 •

4 min read

According to the USDA, one cup of cooked kale contains approximately 1 to 2.2 mg of iron, making it a good source but not necessarily a top-tier one when compared to some other foods. Understanding the full picture of iron absorption from plant sources is key to getting the most out of this nutritious leafy green.

Quick Summary

This article explains if kale is a truly significant source of iron, detailing the type of iron it contains and how to maximize absorption. It compares kale's iron content to other sources, offering practical dietary strategies to enhance its nutritional benefits.

Key Points

Iron Source: Kale is a source of iron, but it is a non-heme, plant-based iron, which is not as easily absorbed as the heme iron found in meat.
Not "Very High": Compared to other iron-rich foods like lentils or red meat, kale's iron content isn't exceptionally high, but it is a good supplementary source.
High in Vitamin C: Kale's high vitamin C content naturally aids in the absorption of its non-heme iron, making it more bioavailable.
Lower Oxalates: Unlike spinach, kale has a lower oxalate content, which further improves the absorption rate of its iron.
Preparation Matters: Cooking kale can increase the amount of iron per serving by reducing its volume, allowing for a greater intake.
Holistic Nutrition: Kale's value extends beyond iron, with rich amounts of vitamins K, A, and C, and other essential minerals contributing to overall health.

Debunking the Iron Myth: How Much Iron Does Kale Really Have?

Despite its reputation as a nutritional powerhouse, the question, “is kale very high in iron?” has a nuanced answer. While kale does contain iron, its quantity and, more importantly, the form of iron present, mean it's not the ultimate iron heavyweight in the vegetable world. A better description would be that kale is a good supplemental source of iron, especially when part of a balanced, iron-conscious diet.

To understand kale's role, we need to look at the different types of dietary iron: heme and non-heme. Heme iron is found exclusively in animal products like red meat, and it is more readily absorbed by the body. Kale, as a plant, contains non-heme iron, which is not absorbed as efficiently. The presence of non-heme iron means that strategies for maximizing absorption become crucial for those relying on plant-based diets.

The Role of Vitamin C in Iron Absorption

A key factor that helps the body absorb non-heme iron is vitamin C. This is where kale shines. Kale is exceptionally rich in vitamin C, with a cup of cooked kale providing a significant portion of the daily recommended intake. The beauty of kale is that it comes with its own built-in absorption booster. By consuming kale, you are simultaneously providing your body with the non-heme iron and the vitamin C it needs to make that iron more bioavailable.

Comparing Kale to Other Iron Sources

It's useful to place kale's iron content in perspective by comparing it with other foods. For instance, while spinach also contains iron, its absorption is often hindered by high levels of oxalic acid. Kale, by contrast, has a much lower oxalate content, which allows for better absorption of its non-heme iron. Similarly, foods like lentils, white beans, and even certain fortified cereals can offer higher raw iron counts per serving. However, the overall nutritional profile and bioavailability matter more than just the raw number.

How to Maximize Iron Intake from Kale

To get the most iron from kale, consider these practical tips:

Combine with Vitamin C-rich foods: Squeeze a little lemon juice over your kale salad or sauté it with bell peppers. The extra vitamin C will significantly boost iron absorption.
Cook it: Cooking kale reduces its volume, meaning you can consume a higher quantity of iron per serving. This is why a cup of cooked kale has more iron than a cup of raw kale.
Avoid certain pairings: Calcium can inhibit non-heme iron absorption. Try to avoid eating kale with dairy products or taking calcium supplements at the same time.
Ferment it: Fermentation can help to increase nutrient bioavailability. Consider making fermented kale, such as kimchi or sauerkraut, to further enhance its nutritional value.

Iron and Kale's Full Nutritional Spectrum

Focusing only on the iron content misses kale's broader nutritional benefits. Beyond iron and vitamin C, kale is packed with vitamins K, A, and C, as well as crucial minerals like magnesium, potassium, and manganese. These nutrients work synergistically to support overall health, from improving bone density and heart health to boosting the immune system. Kale's rich antioxidant content also helps to combat oxidative stress. For this reason, kale is celebrated as a 'superfood' not for any single nutrient, but for its well-rounded nutritional profile.

Comparison of Iron Sources


Food Source	Iron Content (per 100g, cooked)	Iron Type	Bioavailability Factors	Notes
Kale	~1-2 mg	Non-heme	High Vitamin C content boosts absorption. Lower in oxalates than spinach.	Excellent overall nutrient profile.
Spinach	~3.6 mg	Non-heme	High in oxalates, which can inhibit absorption. High Vitamin C helps.	Higher raw iron, but absorption is a challenge.
Lentils	~3.3 mg	Non-heme	Phytic acid can inhibit absorption. Soaking can help.	Excellent source of fiber and protein.
Beef (Heme Iron)	~2-5 mg	Heme	Highly bioavailable and easily absorbed by the body.	More efficient for iron absorption, especially for those with deficiencies.
Fortified Cereal	Variable, can be very high (~67mg)	Non-heme	Added Vitamin C and folic acid in some brands aid absorption.	Excellent for vegetarians needing a major iron boost.

Conclusion: A Balanced Perspective on Kale's Iron

While the popular belief that is kale very high in iron might be an overstatement, it does not diminish kale's role as a valuable dietary component. It is a good source of non-heme iron, and its high vitamin C content makes that iron more accessible to the body. Kale is best viewed not as a sole solution for severe iron deficiency but as a robust, nutrient-dense vegetable that contributes meaningfully to a healthy diet. By cooking kale and pairing it with other vitamin C-rich foods, you can ensure your body is best prepared to absorb its many health benefits.

For more in-depth nutritional information on kale, visit the National Institutes of Health website.

Frequently Asked Questions

No, a cup of cooked kale generally has more iron than a cup of raw kale because the cooking process reduces the volume, allowing you to consume a greater quantity of the leafy green.

For iron absorption, kale is often better than spinach because it has a significantly lower oxalate content. Oxalates bind to iron and can inhibit its absorption, a problem more pronounced with spinach.

To increase non-heme iron absorption from kale, combine it with a source of vitamin C. Squeezing lemon juice over a kale salad or cooking it with bell peppers can be very effective.

While kale is a healthy part of a balanced diet and contributes to iron intake, it is not a cure-all for anemia. Treating severe iron deficiency requires a holistic approach, often including other sources of iron and medical supervision.

The iron in kale (non-heme) is not as bioavailable or easily absorbed by the body as the iron found in meat (heme iron). However, kale's high vitamin C content helps improve the absorption of its non-heme iron.

Massaging kale, often done to soften the leaves for salads, doesn't directly increase its iron content. However, if you massage it with a citrus-based dressing, the vitamin C can help boost the iron's absorption.

Per calorie, kale can have more iron than beef. However, this is not the most helpful comparison, as the heme iron in beef is far more bioavailable and easily absorbed than the non-heme iron in kale.