Plant Iron vs Animal Iron: Will My Iron Levels Be Affected on a Plant-Based Diet?

Do vegans get enough iron?

The topic of iron and a plant-based diet is a really interesting one. It’s similar to ‘protein’ and ‘B12’ in that the hardcore anti-vegan crowds tend to hone in on these things to make you think a vegan diet is incomplete. This blog will aim to:

1. Explain the role of iron in our body
2. The difference between heme and non-heme iron and the iron status of vegans
3. Detail how much iron we need per day
4. How we can source iron from a plant-based diet
5. Tips and tricks to maximise iron absorption.
6. What blood tests accurately measure iron status.

1. What is iron and what is its role in our body?

Iron is an extremely important mineral central to the transport of oxygen around the body in the blood and muscle tissue. Insufficient iron affects the bodies ability to produce normal red blood cells and can result in iron deficiency anemia – a condition affecting women more so than men. People with low iron or anaemia can experience a reduction in energy, reduced immunity, paleness, dizziness and shortness of breath.

2. What is the difference between iron from meat (heme) vs plants (non-heme), and are vegans suffering from iron deficiency more than omnivores?

The iron found in meat is 40% heme iron and 60% non-heme iron, whereas the iron found in plants is 100% non-heme. Studies have indeed shown that non-heme iron is not as readily absorbed as heme iron and as a result, people often label non-heme iron as inferior. There is a caveat here though! When you only consume non-heme iron (vegans), your body adjusts and increases its uptake to suit its needs. The cool thing about this is through this improved iron regulation, non-heme iron can be absorbed when we need it and also down-regulated and not absorbed when our iron stores are high. In comparison, heme iron is so readily absorbed that it can continue to be absorbed even when the body doesn’t need it. Too much iron can cause DNA and their molecule damage and there are studies now linking excess iron intake to Parkinson’s/Alzheimer’s, cardiovascular disease, type 2 diabetes and various cancers.

If we look at the totality of evidence available on vegetarian and vegan iron status, despite vegetarians and vegans typically consuming more dietary iron, they tend to have lower iron stores, both men and women, compared to their omnivore counterparts. When it comes to actually developing iron-deficiency anemia, there is a lot of conflicting data, however, according to a 2016 literature review that looked at 13 studies, vegetarian and vegan pre-menopausal women, in particular, do appear to be at higher risk than their omnivore counterparts. Anecdotally, I can confirm that this certainly appears to be the case and rather than turning a blind eye to what is likely to be fact, I think it’s important to understand the limitations of an animal-free diet and build a plan for success. It’s worth noting, however, that when it comes to nutrient deficiencies worldwide, iron deficiency is the most prevalent, affecting approximately 1 to 1.2 billion people based on the 2019 global population numbers – highlighting that iron deficiency can strike regardless of diet.

3. What are the Recommended Daily Intakes of Iron?

The recommended daily intake for men and postmenopausal women is 8mg, 18mg for women of childbearing age and 27mg for pregnant women (often pregnant women are recommended to take a 30mg iron supplement, particularly those with iron on the lower end of the spectrum). You can find more detailed information about the RDI for Iron here.

Based on the different absorption rates of heme and non-heme iron it is recommended that vegetarians, including vegans, consume 1.8 x the RDI for Iron. This means men and postmenopausal women should aim for 14.4 mg/day, 32.4 mg/day for women of childbearing age and 48.6 mg/day for pregnant women.

4. Where can you find iron in plant-based foods and how can you maximise absorption?

Legumes, including soybeans, tofu and tempeh, are a great source along with oats, pumpkin seeds and dark leafy greens like broccoli, kale and spinach. Dried fruits and in particular apricots, peaches, pears and raisins also pack a lot of iron per serve! The photo above is my homemade kale and basil pesto with pumpkin seeds (an iron-loaded pesto!).

5. What enhances iron absorption?

To increase iron absorption, you want to consume Vitamin C loaded foods with your iron sources. E.g. lemon, bell peppers, oranges, tomatoes, broccoli, kiwi fruit, strawberries, papaya, apricots, cauliflower and pineapple.

How well does Vitamin C work to increase iron absorption?

100ml of orange juice containing 75mg of Vitamin C has been shown to increase the absorption of iron by 4 fold, while other studies have shown 50mg of Vitamin C increases iron absorption 6 fold.

What inhibits iron absorption:

Red Wine
Tea
Coffee
Calcium supplements or super high calcium foods (I.e fortified soy milk)
Avoid the above within an hour either side of eating iron food sources (particularly if you have low iron levels and are actively working to improve them.  If your iron levels are fine, then there is no reason to be overly careful here, just continue doing what are you doing).

6. Blood tests for iron levels?

Determining your iron status is not as simple as just looking at iron stores (serum Ferritin). In fact, there are 4 common tests to evaluate iron status. Typically, the different Iron studies are ordered at the same time as Haemoglobin (Hb) (a broad test for Anemia) or as a result of results showing low Hb levels. Overall, my advice would be to request a serum ferritin blood test and from there you can make informed decisions with your GP or other medical advisors on any changes that may be required within your diet or supplements to consider.

Summary

With a well balanced plant-based diet you can easily get your required daily intake of iron and there are millions of people globally that can attest to this. Iron deficiency isn’t purely a vegan thing or a vegetarian thing and in fact, many non-vegetarians suffer from iron-related anaemia. Typically, iron-related anaemia is associated with chronic blood loss, blood conditions or life periods where there are excess blood requirements and demands on the body, like pregnancy.

Simon