Iron on a Vegan Diet

Iron deficiency is the most common nutritional deficiency worldwide — and it affects omnivores and vegans alike. Here's how to get enough iron from plants and why it's more straightforward than you think.

Haem vs. non-haem iron

There are two types of dietary iron:

Haem iron — found only in meat, fish, and poultry. Absorbed at a rate of 15–35%.
Non-haem iron — found in plants, eggs, dairy, and fortified foods. Absorbed at a rate of 2–20%.

Because non-haem iron is absorbed less efficiently, vegans are advised to consume about 1.8× the standard RDA — approximately 32mg for adult women and 14mg for adult men.

💡 The absorption advantage

Interestingly, non-haem iron absorption is tightly regulated — your body absorbs more when stores are low and less when they're full. Haem iron is absorbed regardless of need, which is why high red meat consumption is linked to iron overload (hemochromatosis) — a condition that increases cancer and heart disease risk.

Best plant sources of iron

Iron content comparison (per 100g)

Metric	Plant source	Animal equivalent
Pumpkin seeds	15mg	Beef liver: 6.5mg
Spirulina	28mg	Beef: 2.6mg
Lentils (cooked)	3.3mg	Chicken: 0.7mg
Tofu (firm)	5.4mg	Salmon: 0.3mg
Fortified oats (100g)	12mg	—
White beans (cooked)	3.7mg	—
Dark chocolate (100g)	11.9mg	—

The Vitamin C trick

Vitamin C (ascorbic acid) dramatically increases non-haem iron absorption — by up to 3–6 times. This is the most effective dietary strategy for improving iron status on a plant-based diet:

Add lemon juice to lentil dishes and salads
Have a glass of orange juice with iron-rich meals
Add bell peppers, tomatoes, or broccoli to iron-rich meals
Have strawberries or kiwi for dessert after dinner

⚠️ What reduces iron absorption

Several compounds inhibit non-haem iron absorption:

Tannins in tea and coffee — avoid these within an hour of iron-rich meals
Calcium — don't have calcium-rich foods with iron-rich meals
Phytates in wholegrains — soaking, sprouting, and fermenting reduces phytate content
Oxalates in spinach and Swiss chard — cook these to reduce oxalate content

What about cooking in iron pans?

Cooking acidic foods (tomato sauce, lemon juice dishes) in cast iron pans does leach small amounts of iron into food. This can meaningfully increase iron intake and is a useful strategy. However, don't rely on it as your primary source.

Should you supplement?

Most vegans who eat a varied diet rich in legumes, seeds, and leafy greens and who pair iron-rich foods with Vitamin C sources do not need to supplement iron. In fact, routine iron supplementation without confirmed deficiency is not recommended, as iron overload can be harmful.

Get a blood test (full blood count + serum ferritin) if you are experiencing: fatigue, cold hands and feet, hair loss, or difficulty concentrating. These can be signs of iron deficiency anaemia.

The evidence on vegan iron status

Studies consistently show that vegans have lower serum ferritin (iron stores) than omnivores, but rates of clinical iron deficiency anaemia are not significantly higher. The body adapts to a lower-iron diet by increasing absorption efficiency. That said, women of reproductive age (due to menstrual blood loss) and pregnant women are at higher risk and may need supplementation.