Boosting Your Iron on a Plant-Based Diet
Eating a plant-based diet can be a really nourishing, healthful way of eating, however there are certain nutrients that can be more difficult to reach optimal levels of without careful dietary planning. Iron is one of these nutrients, particularly for anyone who menstruates, because of the monthly loss of iron that needs replenishing. In this blog post we take a closer look at dietary iron and look at some of the best ways to boost your intake of iron on a vegetarian or vegan plant-based diet.
Haem vs. Non-Haem Iron
There are two types of dietary iron - haem and non-haem. Haem iron - that is, iron that is attached to a haem molecule - is the type found in animal products, such as meat and eggs. Haem is actually a precursor molecule to haemoglobin, the protein that helps to carry oxygen to body tissues via red blood cells. Haem molecules are quite easy for the body to break apart to absorb the iron. Our bodies will absorb around 15-35% of any haem iron consumed.
Non-haem iron, which is not bound to a haem molecule, is the type found in plant foods. This type of iron has much lower biovailability - our bodies can only absorb around 2-20% of any non-haem iron consumed. This means that we need to consume much higher amounts of non-haem iron in order to absorb the equivalent amount we might get from animal products.
How Much Iron Do We Need?
So, we know we need to eat plenty of iron-rich foods in order to reach our optimal iron levels, but how much iron do we actually need each day? According to the Australian Government guidelines, daily iron requirements are:
Infants 0-6 months: 0.2mg/day
Infants 7-12 months: 11mg/day
Children 1-8 years: 9-10 mg/day
Boys 9-18 years: 8-11mg/day
Girls 9-18 years: 8-15mg/day
Men 19+ years: 8mg/day
Women 19-50 years: 18mg/day
Women 50+ years: 8mg/day
Pregnancy: 27 mg/day
Breastfeeding: 9-10mg/day
As you can see, the dietary requirement for AFAB people of reproductive age is much higher than for people in any other age bracket! This is due to the need to replenish iron lost during menstruation. This requirement jumps even higher during pregnancy, when we have significantly higher blood volume and increased needs for building up baby’s iron levels, too.
The Importance of Iron in the Body
So, what is iron actually needed for? Iron is one of the key components of haemoglobin, the protein in red blood cells that is responsible for transporting oxygen to every cell in the body. Every haemoglobin molecule needs for iron molecules in order to function, so maintaining adequate iron levels is essential. Low haemoglobin levels means the body isn’t able to sufficiently deliver oxygen to tissues, disrupting functions such as cellular energy production. This is why iron deficiency leads to symptoms such as shortness of breath and fatigue.
Signs and Symptoms of Iron Deficiency
One of the biggest symptoms of iron deficiency is fatigue. However, fatigue can also be a sign of haemochromatosis (too much iron), which is why blood testing is essential for identifying iron deficiency. Other signs and symptoms of iron deficiency include:
Shortness of breath
Fast heartrate, heart palpitations
Frequent infections and poor immune function
Longer, heavier periods
Pale skin and pale inner eyelids
Poor memory, feel unable to concentrate
Cold hands and feet
Brittle nails
Plant-Based Sources of Iron
There are an abundance of plant-based sources of iron that we can use to boost iron levels through the diet. Below are some of the richest plant sources of iron, including iron content per serve:
Iron-fortified breads and breakfast cereals (18mg per serve) - be aware of the sugar content of breakfast cereals, as many commercial cereals are very high in sugar and low in most other nutrients!
Soy beans (edamame) - 10mg per cup
Dried apricots - 4mg per half cup
Lentils, boiled and drained - 6mg per cup
Spinach, boiled and drained - 6mg per cup
Tofu - 6mg per cup
Quinoa, cooked - 3mg per cup
White button mushrooms, cooked - 3mg per cup
Pumpkin seeds - 3mg per 30g
Kidney beans, cooked - 2mg per half cup
Chickpeas, cooked - 2mg per half cup
Tomatoes, canned - 2mg per half cup
Potato, 1 medium - 2mg
Cashews - 2mg per 30g
Green peas, cooked - 1mg per half cup
Getting Enough Iron on a Plant-Based Diet
Check out these 6 tips for boosting your iron intake on a plant-based diet. These tips are also useful for non-vegans or vegetarians who are struggling with their iron levels!
Load Up on Iron-Rich Veggies and Fruits
Use the list above as a guide for veggies and fruits to use on high-rotation for an iron-rich diet. Some of these veggies can even be added to sauces and soups to boost your iron content - spinach is a great vegetable to add into pasta dishes for an iron boost. Try keeping frozen spinach handy, ready to add in when you need it. Remember it is best to always include as much variety as possible in your diet - focusing too heavily on one particular vegetable can mean you’re missing out on other micronutrients you need for health.
Combine Iron-Rich Foods with Vitamin C-Rich Foods
Ascorbic acid - AKA vitamin C - can actually boost your absorption of non-haem iron by binding to iron in the intestine and making it easier to absorb. Vitamin C can also help to reverse some of the inhibitory effects of nutrients like tannins, which reduce iron absorption.
Some easy iron and vitamin C combinations to try include:
Wilted spinach leaves with a squeeze of lemon
Cooked lentils in a home-made tomato ragu
Tofu and broccoli stir fry
Homemade hummus with plenty of lemon juice
Other vitamin C-rich foods you can use to combine with your iron-rich foods include capsicum, Brussels sprouts, oranges, limes, strawberries, kiwi, potatoes, and even cabbage.
Avoid Drinking Tea and Coffee with Meals
Tea, coffee, and even certain herbal teas are rich in tannins, a type of nutrient that binds with iron and reduces its absorption. To prevent the iron-binding effects of tannins, separate iron-rich meals from your tea or coffee by 2 hours, and consider using a vitamin C-rich food to further reduce iron binding. Herbal teas that are rich in tannins include chamomile, peppermint, and nettle.
Avoid Taking Calcium Supplements Close to Iron-Rich Meals
Calcium and iron compete for absorption, so taking a high-dose calcium supplement with your meal will reduce the amount of iron you get out of that meal. As with tea and coffee, separate any supplements containing calcium from your meals by around 2 hours.
Use Cast Iron Cookware
Using cast iron cookware for preparing your food can actually help to boost your iron levels! When you cook with cast iron, small amounts of iron are leached into your food, helping to increase the iron content. This is one really easy way to boost the iron content of the food you’re eating, even if you aren’t adding additional iron-rich foods to the pot.
Use a Lucky Iron Fish
In a similar vein to cast iron cookware, you can use an iron ingot - a small piece of cast iron - in your cooking to the same effect. The commercially available iron ingot that is most readily available these days is called the Lucky Iron Fish - a small fish (or leaf) shaped piece of cast iron. This fish can be added to the pot as you cook soups, stews or other dishes, to increase the iron content of your food. Alternatively, you can add the iron fish to a pot of water and boil for 10-20 minutes, then drink the cooled water. The iron fish leaches a small enough amount of iron that it doesn’t change the colour or taste of the water, while still being a beneficial boost to your iron intake. In fact, studies of iron-deficient women in Cambodia have shown the Lucky Iron Fish to be successful in improving iron status long-term.
Use a Bio-Available Supplement
If you have very low iron levels, or are struggling to improve your iron status, it might be appropriate for you to take a supplement to help. However, not all iron supplements are created equal! Many iron supplements on the market use forms such as ferric sulphate or ferric citrate, which are not easily absorbed. This can lead to side effects such as constipation. Instead, look for forms such as ferrous bisglycinate, which is much more readily absorbed by the body. This means reduced side effects and better efficacy from your supplement. As with any supplement, it is vital that you consult with a qualified healthcare practitioner before you begin taking an iron supplement. The symptoms of iron deficiency and iron overload are very similar, so checking your iron status before beginning a supplement is important - your healthcare practitioner can refer you for iron studies.
About the Author
Lizzie Stow is a degree-qualified naturopath from Newcastle, Australia.
To find out more about Lizzie, click here.
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References
Armstrong, G. R. (2017). The lucky iron fish: A simple solution for iron deficiency. Blood Advances, 1(5).
Armstrong, G. R., Dewey, C. E., & Summerlee, A. J. S. (2017). Iron release from the lucky iron fish: Safety considerations. Asia Pacific Journal of Clinical Nutrition, 1.
Ems, T., St Lucia, K., & Huecker, M. R. (2022). Biochemistry, iron absorption. StatPearls.
Lynch, S. R., & Cook, J. D. (1980). Interaction of vitamin C and iron. Annals of the New York Academy of Sciences, 355, 32–44.
National Health and Medical Research Council. (2006). Iron. https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/iron
National Institutes of Health Office of Dietary Supplements. (2022). Iron—Fact sheet for health professionals. https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/
Rodriguez-Vivaldi, A. M., & Beerman, K. (2018). Testing the efficacy of the lucky iron fish in reversing iron deficiency anaemia in rural, impoverished regions of Guatemala. 2.