Is there more iron in spinach or broccoli? A Complete Comparison

December 3, 2025 •

4 min read

According to USDA data, 100 grams of raw spinach contains significantly more iron than the same serving size of raw broccoli. However, the crucial question, "Is there more iron in spinach or broccoli?", involves more than just total content—it depends on how much iron your body can actually absorb from each vegetable. This article explores the raw numbers and the science of bioavailability to give you the complete picture.

Quick Summary

This article provides a detailed comparison of the iron content in spinach versus broccoli, examining not only the raw nutritional data but also the key factor of iron absorption. It highlights how bioavailability influences the real iron benefit from plant-based sources and offers tips for maximizing your intake from these healthy vegetables.

Key Points

Spinach has more iron: Raw spinach contains significantly more iron per 100 grams than raw broccoli.
Bioavailability is key: The iron in plants (non-heme) is less readily absorbed by the body than heme iron from meat.
Oxalates hinder absorption: Spinach contains oxalates that bind to iron and reduce its bioavailability.
Broccoli has higher bioavailability: Research indicates that the iron in broccoli is more easily absorbed than that found in spinach.
Vitamin C boosts absorption: Both vegetables contain Vitamin C, which can significantly enhance non-heme iron absorption when consumed together.
Consider both vegetables: For a well-rounded diet, include both spinach and broccoli to benefit from their unique nutritional profiles and health benefits.

The Raw Iron Content: Spinach vs. Broccoli

At first glance, a simple comparison of raw nutritional data from sources like the USDA reveals that spinach is the clear winner in total iron content. While the exact values can vary based on growing conditions, variety, and maturity, typical figures show a significant difference per 100 grams.

Raw Spinach: Contains roughly 2.7 mg of iron per 100 grams.
Raw Broccoli: Offers around 0.6 to 0.8 mg of iron per 100 grams.

These raw numbers alone might lead you to believe that spinach is the superior choice for iron. However, this is only part of the story. The form of iron and other compounds present in these vegetables dramatically affect how much iron your body can actually absorb and utilize.

The Crucial Factor: Bioavailability and Absorption

The iron found in plants is called non-heme iron, which is less readily absorbed by the human body compared to the heme iron found in meat, poultry, and fish. Both spinach and broccoli contain non-heme iron, but how efficiently your body can absorb it differs significantly between the two.

Inhibitors of Iron Absorption

Spinach is notoriously high in oxalic acid (or oxalates), a compound that binds with iron and other minerals like calcium, making them harder for the body to absorb. This means that while spinach has a higher total iron content on paper, the presence of oxalates reduces its bioavailability. Several sources debunk the myth that spinach is a primary iron source, citing this inhibitory effect.

Broccoli, on the other hand, does not have a high oxalate content. Some studies suggest that the relative bioavailability of iron in broccoli is higher than in spinach, which means a larger percentage of the iron it contains can be absorbed by the body. This is a critical nuance often overlooked in basic nutritional comparisons.

Enhancers of Iron Absorption

Crucially, both vegetables are excellent sources of Vitamin C, a powerful nutrient that significantly enhances the absorption of non-heme iron. Combining iron-rich plant foods with Vitamin C is a well-documented strategy to maximize absorption. While spinach is a good source of Vitamin C, broccoli is particularly rich in it, often containing nearly three times more per 100 grams than spinach.

Making the Most of Your Greens

To get the most iron from your leafy greens, you should focus on cooking methods and food pairings that optimize absorption. Here are some strategies:

Pairing with Vitamin C: Serve your spinach or broccoli with a splash of lemon juice, add bell peppers to your meal, or include tomatoes.
Cooking in a Cast-Iron Skillet: Cooking acidic foods in cast-iron cookware can increase the iron content of the meal.
Avoid Inhibitors: Try not to consume coffee, tea, or dairy products at the same time as your iron-rich vegetable meal, as they can inhibit absorption.

Spinach vs. Broccoli: A Nutritional Breakdown


Feature	Spinach (per 100g, raw)	Broccoli (per 100g, raw)
Iron (mg)	Approx. 2.7 mg	Approx. 0.7 mg
Bioavailability	Lower due to high oxalate content	Higher than spinach; relatively better absorbed
Vitamin C (mg)	Approx. 28 mg	Approx. 91 mg
Vitamin K (mcg)	Approx. 483 mcg	Approx. 102 mcg
Calcium (mg)	Approx. 99 mg	Approx. 47 mg

Beyond Iron: A Broader Nutritional View

While the iron story is complex, a broader view shows that both vegetables offer distinct and valuable nutritional benefits:

Spinach: A nutrient powerhouse, it offers higher amounts of Vitamin K, Vitamin A, and folate. Its high levels of antioxidants like lutein and zeaxanthin are also beneficial for eye health.
Broccoli: An excellent source of Vitamin C, it also contains more fiber and potent anti-cancer compounds like sulforaphane.

There's a strong argument to be made for incorporating both into your diet to reap the full spectrum of nutrients. Each vegetable provides unique health advantages, from promoting heart health to reducing inflammation. Neither is definitively "better" than the other; rather, they are complementary.

Conclusion

To answer the question, "Is there more iron in spinach or broccoli?", yes, spinach has a higher raw iron content. However, due to its high oxalate content, the iron is less bioavailable than the iron in broccoli. This means that your body might absorb a smaller fraction of spinach's total iron. Ultimately, the best strategy is not to choose one over the other but to include both in a balanced diet. By combining them with Vitamin C-rich foods, you can maximize your iron absorption and benefit from the full range of vitamins and minerals these incredible greens provide. For more insights on non-heme iron, consult reliable sources like Harvard's T.H. Chan School of Public Health.

Frequently Asked Questions

Cooking methods can affect nutrient content. While cooked spinach still has more iron than cooked broccoli, the absorption is still hindered by oxalates. Steaming broccoli, however, is a great way to preserve its high Vitamin C content, which helps with iron absorption.

To increase iron absorption from spinach, pair it with foods rich in Vitamin C, such as bell peppers, citrus fruits, or tomatoes. You can also cook it in a cast-iron skillet.

The iron in spinach is not absorbed well because it is non-heme iron and is bound by high levels of oxalic acid present in the vegetable. This chemical compound inhibits the body's ability to absorb the mineral efficiently.

While not as high in total iron as spinach, broccoli can be considered a better source of usable iron because its iron is more bioavailable (more easily absorbed). It is also rich in Vitamin C, which further aids in iron absorption.

Spinach provides more Vitamin K and Vitamin A, while broccoli offers significantly more Vitamin C and fiber. Both are excellent sources of different vitamins, minerals, and antioxidants.

Per weight, cooked spinach contains more iron because the cooking process removes water and concentrates the nutrients. However, the iron's bioavailability is still affected by oxalates.

Neither is definitively better, as both offer unique health benefits. Spinach excels in Vitamin K and A, while broccoli is a superior source of Vitamin C and fiber. A balanced diet should incorporate both vegetables to gain a broader spectrum of nutrients.