Foods rich in iron. The best dietary sources and how to eat them
The most effective dietary sources of iron, how haem and non-haem iron differ, andthe food combinations that make the biggest difference to absorption.
Iron is one of the most important minerals in the human diet, and one of the most commonly deficient. In the UK, iron deficiency is the most widespread nutritional deficiency. Particularly among women of reproductive age, pregnant women, and people eating predominantly plant-based diets. Getting enough iron from food is achievable, but it requires knowing which foods are actually rich sources, understanding the difference between the two forms of dietary iron, and knowing which combinations improve or reduce how much your body absorbs.
"Iron is not just about eating meat. Understanding the difference between haem and non-haem iron, and how to improve absorption of the latter, changes how you approach the whole question."
Haem iron vs non-haem iron. Why the distinction matters
Notall dietary iron is the same. Iron comes in two forms, and the difference between them significantly affects how much your body actually absorbs.
Haem iron is found in animal products. Red meat, poultry, fish, and seafood.
It is absorbed at around 15% to 35% efficiency. The body absorbs haem iron directly, and its absorption is relatively consistent regardless of what else you eat with it.
Non-haem iron is found in plant foods. Lentils, beans, tofu, spinach, fortified cereals, seeds, and nuts. It is absorbed at a much lower rate - Typically 2 to 20 percent, plus its absorption is significantly affected by other foods eaten at the same meal. Vitamin C dramatically improves non-haem iron absorption. Tannins in tea and coffee, calcium in dairy, and phytates in wholegrains all reduce it.
This matters particularly for people eating plant-based or vegetarian diets, where all dietary iron is non-haem. It is entirely possible to meet iron requirements from plant foods, but it requires more deliberate food choices and combinations.
Approximate iron content per 100g serving
Liver (beef, cooked)6.5mg — haem
Pumpkin seeds8.8mg — non-haem
Lentils (cooked)3.3mg — non-haem
Spinach (cooked)3.6mg — non-haem
Tofu (firm)2.7mg — non-haem
Beef (lean, cooked)2.7mg — haem
Kidney beans (cooked)2.5mg — non-haem
Sardines (tinned)2.9mg — haem
Cashews6.7mg — non-haem
Dark chocolate (70%+)11.9mg — non-haem
Fortified breakfast cerealup to 8mg — non-haem
Chickpeas (cooked)2.9mg — non-haem
UK recommended daily intake: 8.7mg (men and post-menopausal women) | 14.8mg (women aged 19–50)
The best animal-based iron sources
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Most concentrated
Liver
Beef liver provides around 6.5mg per 100g of highly absorbable haem iron. It is also rich in vitamin A, B12, folate, and copper. Including it once or twice a month provides a meaningful boost to iron status. Chicken liver is a milder-tasting alternative with similar nutritional properties. Note: liver is not recommended for pregnant women due to its high vitamin A content.
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Reliable source
Red meat
Beef, lamb, and venison are reliable haem iron sources. A 100g serving of lean cooked beef provides around 2.7mg. Regular but moderate inclusion of red meat, two to three times per week, contributes meaningfully to iron intake. Choosing lean cuts reduces saturated fat intake while maintaining iron content.
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Broad nutrition
Sardines and oily fish
Sardines, mackerel, and other oily fish provide haem iron alongside omega-3, vitamin D, calcium (in tinned sardines, from the bones), and selenium. Tinned sardines are one of the most practically accessible iron-rich foods. Inexpensive, shelf-stable, and nutritionally dense.
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Highest of all
Shellfish
Clams, mussels, and oysters are among the richest haem iron sources of any food. Clams in particular are exceptionally high. A 100g serving can provide more than 25mg of iron. Shellfish is not eaten frequently enough in the UK to serve as a regular iron source for most people, but it is worth noting for those who do eat it.
The best plant-based iron sources
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Richest plant source
Pumpkin seeds
One of the richest plant-based iron sources at around 8.8mg per 100g. A 30g serving provides around 2.6mg. Also rich in magnesium, zinc, and healthy fats. Add to porridge, salads, soups, or eat as a snack.
~2.6mg per 30g serving
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Versatile staple
Lentils
Around 3.3mg per 100g cooked, plus folate, fibre, and protein. Red, green, and Puy lentils all provide similar amounts. Including lentils in two to three meals per week makes a significant contribution to dietary iron.
3.3mg per 100g
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Protein and iron
Tofu
Firm tofu provides around 2.7mg per 100g, making it both a protein and an iron source for plant-based diets. Pairing tofu with vitamin C-rich vegetables in stir-fries and curries maximises iron absorption.
2.7mg per 100g
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Worth noting
Dark chocolate
Dark chocolate at 70 percent cocoa or above contains around 11.9mg per 100g. A typical 30g serving provides around 3.5mg of non-haem iron. The absorption rate is variable, but it remains a genuine dietary source for those who include it regularly.
~3.5mg per 30g serving
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Check the label
Fortified cereals
Many breakfast cereals in the UK are fortified with iron. The amount varies considerably between products, with some providing up to 8mg per serving. Eating fortified cereal with a glass of orange juice significantly improves non-haem iron absorption.
Up to 8mg per serving
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Pair with vitamin C
Spinach and leafy greens
Cooked spinach provides around 3.6mg per 100g. Oxalates reduce absorption somewhat, but it remains a useful source, particularly when eaten alongside vitamin C-rich foods. Kale, Swiss chard, and watercress are also worth including.
3.6mg per 100g cooked
Food combinations that make a real difference
Eating vitamin C-rich foods alongside non-haem iron sources significantly increases absorption. Practical combinations: lentil soup with a squeeze of lemon, tofu stir-fry with red peppers, spinach salad with orange segments, fortified cereal with orange juice. Avoid tea, coffee, and calcium-rich dairy within an hour of your main iron-rich meal.
How much iron do you actually need?
The UK recommended daily intake is 8.7mg for men and post-menopausal women, and 14.8mg for women aged 19 to 50. The higher requirement for women ofreproductive age reflects iron losses through menstruation. Women with heavy periods may need to pay particularly close attention to dietary iron, and some will require supplementation.
People eating plant-based diets are often advised to aim for higher intakes than the standard recommendation. Around 1.8 times higher because of the lower absorption rate of non-haem iron compared to haem iron.
Signs you may not be getting enough
Persistent fatigue, breathlessness during normal activity, pale skin, frequent headaches, cold hands and feet, and difficulty concentrating are the most common signs of iron deficiency. If several of these apply, read our full guide to symptoms of low iron — and speak with your GP about getting a blood test.
"The most effective approach to dietary iron is not dramatic. It is consistent inclusion of a few key foods, combined thoughtfully, every day."
Shellfish, particularly clams, are among the highest sources by weight. In practical everyday terms, beef liver, pumpkin seeds, dark chocolate, and fortified cereals are the most accessible high-iron foods. Pumpkin seeds are the standout plant-based source at around 8.8mg per 100g.
Eat vitamin C-rich foods at the same meal, including orange juice, peppers, tomatoes, and lemon juice. Avoid tea, coffee, and high-calcium foods within an hour of iron-rich meals. Soaking and cooking dried legumes from scratch reduces phytate content, which also improves absorption.
Yes, but it requires more attention to food choices and combinations than an omnivorous diet. Plant-based iron sources are abundant, including lentils, tofu, pumpkin seeds, fortified foods, dark chocolate, and leafy greens. But non-haem iron absorption is lower than haem iron. Pairing these foods consistently with vitamin C, and being aware of foods that inhibit absorption, makes a significant difference.
Spinach does contain iron, around 3.6mg per 100g when cooked, but its oxalate content reduces how much is absorbed. It is a useful contributor to dietary iron rather than a primary source. Cooked spinach alongside vitamin C-rich foods maximises what you absorb from it.
Only if a blood test confirms deficiency. Iron supplementation without confirmed need is not recommended. Excess iron is not easily excreted and can cause harm at high doses. If you suspect deficiency based on symptoms, speak with your GP about testing ferritin and haemoglobin first.
Know how your body absorbs iron.
Boone analyses your genetic profile for iron absorption and transport variants — showing you whether your body handles dietary iron efficiently or whether you may need to be more deliberate about sources and food combinations. Connected to your real diet through the food log and micro nutrition scores.
Download the Boone app and discover what your nutritional picture looks like.
