What to take to improve iron absorption? Your comprehensive guide

October 14, 2025 •

5 min read

Affecting up to 25% of the global population, iron deficiency is the world's most common nutrient deficiency and a leading cause of anemia. Understanding what to take to improve iron absorption is crucial, as the body's ability to absorb dietary iron is not a simple process and can be significantly influenced by what you eat and when you eat it.

Quick Summary

Maximize iron absorption by strategically pairing your meals and supplements with enhancing nutrients like vitamin C and avoiding inhibitors such as calcium and polyphenols. Combining meat or fish with plant-based iron sources also boosts uptake. Proper meal timing and cooking methods are also important factors in improving iron levels.

Key Points

Boost Absorption with Vitamin C: Pairing iron-rich foods with sources of Vitamin C like citrus fruits, bell peppers, and strawberries significantly enhances the absorption of non-heme iron.
Combine Heme and Non-Heme Iron: Eating animal-based heme iron sources, which are more bioavailable, alongside plant-based non-heme iron can increase overall absorption.
Avoid Inhibitors at Mealtime: Do not consume calcium-rich foods, coffee, or tea at the same time as iron-rich meals to prevent reduced absorption.
Mind Your Supplements: For best results, take iron supplements on an empty stomach with a source of vitamin C, and separate them from calcium supplements.
Utilize Cooking Techniques: Cooking in cast-iron pans and soaking legumes or grains can help reduce absorption-inhibiting compounds and increase iron content.
Include Vitamin A in Your Diet: This vitamin helps mobilize stored iron, so including foods like sweet potatoes and carrots supports iron status.
Pay Attention to Timing: For supplements, morning may be the best time due to lower hepcidin levels, which regulate iron absorption.

Iron is an essential mineral vital for producing hemoglobin, the protein in red blood cells that carries oxygen throughout the body. The efficiency of iron absorption from food is not consistent; it depends heavily on the type of iron, as well as the other foods and drinks consumed with it. By being mindful of your dietary choices, you can make a big difference in your body's ability to utilize this critical nutrient.

Understanding Iron: The Two Main Types

To effectively improve absorption, you must first understand the two forms of dietary iron:

Heme iron: This type is found in animal products that contain hemoglobin, such as red meat, poultry, and fish. It is highly bioavailable, meaning the body absorbs it more efficiently, with rates as high as 40%.
Non-heme iron: Found in plant-based sources like grains, beans, lentils, nuts, seeds, and leafy green vegetables, non-heme iron is less efficiently absorbed by the body. Fortified foods also contain this form of iron. Vegetarians and vegans, who rely solely on non-heme sources, often need to consume more iron or use specific absorption-enhancing strategies.

Key Nutrients to Boost Iron Absorption

The Power of Vitamin C

Vitamin C (ascorbic acid) is perhaps the most well-known enhancer of non-heme iron absorption. It works by capturing non-heme iron and storing it in a form that is more easily absorbed by the body. This makes it an invaluable partner for those following a plant-based diet, but it benefits everyone looking to increase their iron uptake. To leverage this effect, consume vitamin C-rich foods alongside your iron sources.

Excellent sources of Vitamin C include:

Citrus fruits (oranges, lemons, grapefruit)
Bell peppers (red and yellow)
Strawberries
Broccoli
Melons
Tomatoes
Kiwi fruit

Vitamin A and Beta-Carotene

Another important nutrient for iron status is Vitamin A, which plays a critical role in releasing stored iron. Beta-carotene, a compound found in plants, can be converted into Vitamin A by the body. Including foods rich in these nutrients can help ensure that your body can effectively access its iron reserves.

Foods high in Vitamin A and Beta-Carotene include:

Carrots
Sweet potatoes
Spinach and kale
Squash
Apricots

Combining Heme and Non-Heme Sources

For those who consume animal products, combining sources of heme and non-heme iron in the same meal can significantly improve the absorption of the non-heme iron. For instance, adding chicken or fish to a lentil or bean dish can boost the non-heme iron uptake.

Dietary Factors that Inhibit Iron Absorption

Just as some foods boost iron absorption, others can hinder it. To maximize your intake, it's equally important to know what to avoid consuming with your iron-rich meals.

The Problem with Phytates and Oxalates

Phytates, or phytic acid, are found in whole grains, cereals, legumes, nuts, and seeds. Even small amounts can significantly decrease iron absorption. Similarly, oxalates, present in some leafy greens like spinach, bind to iron and inhibit absorption. To mitigate the effect of phytates, you can soak legumes and grains properly before cooking.

The Calcium Conflict

Calcium is an essential mineral for bone health, but it has been shown to inhibit the absorption of both heme and non-heme iron. To minimize this effect, it's recommended to consume calcium-rich foods and supplements at a separate time from your iron-rich meals. A one to two-hour buffer is often sufficient.

Polyphenols in Your Cup

Polyphenols are compounds found in plant-based beverages like coffee, tea, and red wine. They can bind with iron and carry it out of the body, significantly reducing absorption. To avoid this, consume these beverages between meals rather than with them.

A Strategic Approach to Meals and Supplements

Beyond specific nutrients, how you consume your iron also matters. Following a few simple rules can help make your body's absorption more efficient.

Timing of supplements: If taking an iron supplement, it's often best absorbed on an empty stomach, though some find it causes upset stomach. If you do experience discomfort, taking it with a small amount of vitamin C-rich food can help. Taking supplements in the morning may also be beneficial, as iron absorption is regulated by the hormone hepcidin, which is lower in the morning.
Cooking with cast iron: Using a cast-iron skillet or pan can increase the iron content of your meals. The effect is particularly notable for high-moisture foods cooked for longer periods, like stews or sauces.
Consider supplement form: Ferrous iron supplements (like ferrous sulfate, fumarate, or gluconate) are generally absorbed better than ferric forms.
Probiotics: Maintaining a healthy gut microbiome with probiotics can also aid in overall nutrient absorption, including iron.

Comparison: Enhancers vs. Inhibitors of Iron Absorption


Factor	Role in Absorption	Example Foods/Sources	Best Practice
Vitamin C	Enhancer: Helps convert non-heme iron into a more absorbable form.	Oranges, bell peppers, strawberries, kiwi.	Consume with iron-rich foods or supplements.
Heme Iron	Enhancer: Highly bioavailable and boosts non-heme absorption.	Red meat, poultry, fish, shellfish.	Combine with non-heme iron sources in meals.
Phytates	Inhibitor: Binds to iron, reducing absorption.	Whole grains, legumes, nuts, seeds.	Soak grains and legumes before cooking to reduce phytate levels.
Calcium	Inhibitor: Can hinder the absorption of both heme and non-heme iron.	Dairy products, calcium supplements.	Separate intake from iron supplements and iron-rich meals by at least 1-2 hours.
Polyphenols	Inhibitor: Binds to iron, especially from plant sources.	Tea, coffee, red wine, cocoa.	Wait a couple of hours after an iron-rich meal to consume.
Vitamin A	Enhancer: Helps release stored iron within the body.	Carrots, sweet potatoes, spinach, kale.	Include in your regular diet alongside iron sources.

Conclusion

Improving iron absorption is not about eating more iron but about eating smarter. By being strategic with your food choices—prioritizing enhancers like vitamin C and heme iron while avoiding inhibitors such as calcium and polyphenols—you can significantly increase the amount of iron your body absorbs from both food and supplements. Experimenting with combinations like a spinach salad with strawberries and lemon juice can be both delicious and effective. If you have concerns about iron deficiency, always consult with a healthcare provider or a registered dietitian to determine the best course of action for your needs.

For more information on the bioavailability of iron, you can consult the NIH Office of Dietary Supplements fact sheet.

Frequently Asked Questions

No, it is not recommended to take calcium and iron supplements at the same time. Calcium can interfere with iron absorption, so it is best to take them at different times of the day, with at least a one to two-hour gap.

You should wait a couple of hours after consuming an iron-rich meal before drinking coffee or tea. The polyphenols in these beverages can significantly hinder iron absorption.

Some leafy greens, like spinach, contain oxalates, which can inhibit iron absorption. However, the effect is less pronounced when paired with a strong iron enhancer like vitamin C. Other greens, like kale and watercress, are good iron sources.

Yes, heme iron is more easily absorbed by the body than non-heme iron. It is less affected by other dietary factors. However, it is possible to get enough iron from non-heme sources by employing absorption-enhancing strategies.

Yes, cooking food in a cast-iron skillet can increase its iron content. The amount of iron that leaches into the food is dependent on the food's moisture content and cooking time.

Yes, Vitamin A and beta-carotene are also known to help with iron absorption. They play a role in mobilizing stored iron and are found in foods like carrots, sweet potatoes, and kale.

Phytates are compounds found in whole grains, cereals, nuts, and legumes that bind to iron and inhibit absorption. You can reduce their content by soaking beans and lentils before cooking.