Which has more iron: Beetroot or Spinach? A Nutritional Deep Dive

October 14, 2025 •

4 min read

While the cartoon character Popeye solidified spinach's reputation as the ultimate iron-rich food, a crucial nutritional factor known as bioavailability actually complicates the question of which has more iron, beetroot or spinach. It's not just about the number on the nutrition label; it's about what your body can actually absorb.

Quick Summary

Spinach generally contains a higher total amount of iron per serving than beetroot. However, the iron in spinach is less absorbable due to high levels of oxalates, whereas beetroot's iron may be more bioavailable. For maximum benefit, dietary context and preparation methods are key.

Key Points

Spinach has more total iron: On a per-cup basis, especially when cooked, spinach contains a higher quantity of iron than beetroot.
Iron absorption is crucial: Despite spinach's higher content, its iron is less bioavailable, meaning the body absorbs less of it.
Oxalates in spinach hinder absorption: Spinach is very high in oxalates, which bind to iron and prevent its uptake by the body.
Beetroot's iron is more bioavailable: With a lower oxalate content, the iron in beetroot is more easily absorbed by the body.
Vitamin C enhances absorption: Consuming either vegetable with a vitamin C source, like citrus or bell peppers, can significantly increase iron absorption.
Both offer unique health benefits: Beyond iron, spinach is rich in Vitamin K and A, while beetroot provides nitrates that can lower blood pressure.

Total Iron Content: A Misleading Metric?

When comparing the total iron content by weight, cooked spinach typically contains more iron than cooked beetroot. The perception of spinach as an iron powerhouse originated from a historical decimal point error, which vastly overestimated its iron content. While that myth has been debunked, spinach is still a very good source of iron, especially when cooked down.

Spinach: A cup of cooked spinach can contain significantly more iron than a cup of cooked beetroot. Raw spinach contains less iron by weight due to its high water content.
Beetroot: A cup of cooked beetroot contains less total iron than cooked spinach. However, the story doesn't end with a simple comparison of raw figures. How your body utilizes this iron is far more important.

The Role of Oxalates and Bioavailability

Bioavailability refers to the proportion of a nutrient that is absorbed by the body from the food source. The primary reason for the difference in iron absorption between these two vegetables lies in compounds called oxalates.

Spinach's high oxalate content: Spinach contains high levels of oxalic acid, which binds to iron and other minerals, blocking their absorption in the gut. This dramatically reduces the amount of iron your body can actually use, despite the high total amount present. While cooking can help break down some oxalates, it does not eliminate the absorption issue completely.
Beetroot's lower oxalate content: Beetroot has a much lower oxalate concentration than spinach. This means that a higher percentage of the non-heme iron it contains is available for the body to absorb.

The Vitamin C Advantage

Another factor influencing absorption is the presence of other nutrients. Vitamin C is a powerful enhancer of non-heme iron absorption.

Beetroot's natural vitamin C: Beetroot contains a moderate amount of vitamin C, which works to improve the bioavailability of its iron.
Enhancing spinach's iron: You can significantly boost the iron absorption from spinach by pairing it with a source of vitamin C, such as a squeeze of lemon juice, some bell peppers, or strawberries.

Comparison Table: Beetroot vs. Spinach Iron Profile


Feature	Spinach (Cooked)	Beetroot (Cooked)
Total Iron (per cup)	~5.7 mg	~2.9 mg
Oxalate Content	Very High	Lower
Iron Bioavailability	Low (inhibited by oxalates)	Higher (lower oxalate content)
Natural Vitamin C	Moderate	Moderate
Key Additional Nutrients	Vitamin K, Vitamin A, Folate	Folate, Nitrates, Fiber

Maximizing Iron Absorption from Your Diet

For vegetarians, vegans, or anyone looking to boost their iron intake from plant sources, it is crucial to focus on absorption rather than just raw content. Here are some strategies:

Pair with Vitamin C: Always combine plant-based iron sources with a food rich in vitamin C. For example, add tomatoes to a spinach dish or drink a small glass of orange juice with your meal.
Cook Leafy Greens: Cooking reduces the volume of greens and can help break down some of the oxalates in spinach, making more iron available.
Avoid Inhibitors: Try to consume calcium-rich foods, tea, and coffee at a different time of day than your iron-rich meal, as they can inhibit iron absorption.
Use a Cast Iron Pan: Cooking with cast iron cookware can significantly increase the iron content of your food.
Combine Sources: Eating a variety of iron-rich plant foods like lentils, chickpeas, and seeds alongside your greens will provide a broader range of nutrients and ensure better absorption.

Beyond Iron: The Health Benefits of Beetroot and Spinach

While the iron discussion is important, both vegetables offer a wealth of other health benefits that make them valuable dietary additions.

Beetroot benefits: Rich in nitrates, beetroot can help lower blood pressure and improve athletic performance. The antioxidants known as betalains help reduce inflammation. Beetroot is also a great source of folate and fiber.
Spinach benefits: High in Vitamin A, Vitamin K, and folate, spinach supports bone health, vision, and cognitive function. It also contains antioxidants that combat oxidative stress.

Conclusion

In the simple battle of total iron content, cooked spinach technically has more iron per cup than cooked beetroot. However, this is only a partial truth. The high oxalate content in spinach significantly hinders iron absorption, a factor that is less of an issue with beetroot. Ultimately, beetroot's iron may be more readily usable by the body. The best approach is not to pick one over the other, but to incorporate both into a balanced diet. By understanding the role of bioavailability and pairing these vegetables with vitamin C, you can maximize your iron intake from both sources. For individuals with anemia, a varied diet is key, and it's always best to consult a healthcare professional for personalized advice.

For more detailed nutritional comparisons, you can explore resources like Food Struct, which provides in-depth breakdowns of different foods.(https://foodstruct.com/nutrition-comparison/spinach-vs-beetroot)

Frequently Asked Questions

Yes, cooking spinach condenses the leaves, resulting in a higher iron concentration per cup compared to raw spinach. It also helps break down some of the oxalates, which can slightly improve iron availability.

Relying on a single plant-based source for your iron needs is not recommended due to low bioavailability. A balanced diet with a variety of iron-rich foods and absorption enhancers is the best approach.

The most effective way is to pair spinach with a food high in vitamin C, such as a citrus dressing, tomatoes, or bell peppers. Avoiding coffee or tea with your meal also helps.

No. The iron in spinach and beetroot is non-heme iron, found in plant-based foods, which is less readily absorbed than the heme iron found in animal products like meat.

Yes. Other foods like lentils, chickpeas, and certain fortified cereals can offer more and better-absorbed non-heme iron. Pair them with vitamin C for optimal results.

For most healthy individuals, the oxalate content in spinach is not a concern, especially when consumed in moderation. However, individuals prone to kidney stones should be mindful of their intake.

Beetroot juice is rich in both iron and vitamin C, making it a good dietary supplement for promoting red blood cell production. Studies have shown it can increase hemoglobin levels in anemic individuals.