A frequent question asked about plant-based (vegan) diets is “How do you get enough iron?”
This post will provide the information you need to reach your daily iron needs while eating a well-balanced, whole food, plant-based diet.
Iron deficiency is the most common nutritional deficiency in the world. In Australia, 1 in 8 people are not consuming enough iron. It’s thought that as a vegan, you will automatically consume less iron. Studies have actually shown that vegan/plant-based diets are typically higher in iron compared to non-vegetarian diets or lacto-ovo-vegetarian diets (no meat, although still includes dairy and eggs). There’s also evidence that Iron Deficiency Anaemia rates are similar between vegetarians and non-vegetarians. These studies have shown that vegetarians generally have lower iron stores (indicated by serum ferritin), however still within a normal range.
Why do you need iron?
Iron is an essential mineral responsible for transporting oxygen around your body via hemoglobin in your blood as well as storing and using oxygen as myoglobin in your muscles. It also plays a role in creating red blood cells, ensuring your immune system is functioning effectively, allowing your body to produce enough energy, helping your thyroid to perform optimally, allowing your liver to carry out detoxification and acting as a cofactor in neurotransmitter production (such as serotonin, a neurotransmitter responsible for happiness). It’s a crucial nutrient for pregnancy and breastfeeding, which contributes to a child’s cognitive and physical development. So, you can see how important this mineral is.
What are the signs and symptoms of Iron Deficiency Anaemia?
The common signs and symptoms of Iron Deficiency Anaemia are:
- Fatigue, tiredness, lethargy, weakness
- Pale skin, pale conjunctiva (inside of eyelids), dark circles under eyes
- Breathlessness, dizziness, fainting
- Lowered immunity, constant infections, more frequent colds
- Headaches
- Heart palpitations (fast, fluttering or pounding heartbeat), chest pain
- Cyanosis of the nail bed (pale or blue-tinge), koilonychia (spoon-shaped nails), brittle nails
- Dry and brittle hair, hair loss
- Sore/inflamed tongue, dysphagia (difficulty swallowing)
- Sores in the corners of the mouth
- Cold hands and feet, increased sensitivity to cold temperatures
- Poor appetite (especially in infants and children)
- Pica (cravings for unusual substances such as ice, cornstarch, licorice, chalk, dirt, or clay)
- Mood changes, depression, apathy
- Impaired brain function, lack of mental alertness, poor memory and concentration
- Lowered tolerance to exercise
- Poor thyroid function
- Increased heavy metal toxicity
How do you know if you have Iron Deficiency Anaemia?
I can’t stress enough to never self-diagnose. Always talk to a health practitioner before taking iron supplements. Your symptoms may not be related to low iron and too much of this nutrient can actually be harmful. For example, in a rather common hereditary condition, haemochromatosis, the body continues to absorb and store iron from food, causing tissue and organ damage.
The best way to have your iron levels assessed is to get a referral from your doctor for a blood test. There are three varying levels of iron deficiency that can be easily assessed by a blood test. You may have low iron stores (indicated by low serum ferritin and reduced iron-binding capacity), early functional iron deficiency (indicated by decreased transferrin saturation) or Iron Deficiency Anaemia (indicated by low haemoglobin and reduced mean cell volume). If you’re seeing a natural health practitioner, such as a nutritionist or naturopath, they’ll ask you to bring in your test results to determine what level of treatment you require.
How much iron do you need each day?
The amount of iron your body requires each day depends on your age, gender and whether you are pregnant or breastfeeding. Your requirements may also be higher if you experience heavy menstruation, have chronic intestinal conditions such as Coeliac Disease, Crohn’s Disease or Inflammatory Bowel Disease, donate blood regularly, have experienced a large amount of blood loss (such as with childbirth or surgery), or are correcting an iron deficiency. Interestingly, most of your iron requirements are met through the process of your body recycling its own red blood cells.
The Recommended Dietary Intake’s (RDI’s) are listed below for the various age groups and genders.
Iron RDI for infants & children
| Age group | Infants 7-12 months |
Children 1-3 years |
Children 4-8 years |
| Recommended Dietary Intake (RDI) | 11 mg | 9 mg | 10 mg |
Iron RDI for adolescents
| Age group | Adolescent boys & girls 9-13 years |
Adolescent boys 14-18 years |
Adolescent girls 14-18 years |
| Recommended Dietary Intake (RDI) | 8 mg | 11 mg | 15 mg |
Iron RDI for adults
| Age group | Men 19 years + |
Women 19-50 years |
Women 51 years + |
| Recommended Dietary Intake (RDI) | 8 mg | 18 mg | 8 mg |
Iron RDI for pregnancy and breastfeeding
It’s important for pregnant women to monitor their iron levels during pregnancy as iron deficiency can lead to premature childbirth, low birthweight and an increased risk of infant mortality.
| Age group | Pregnancy | Breastfeeding/ lactation 18 years + |
Breastfeeding/ lactation <18 years |
| Recommended Dietary Intake (RDI) | 27 mg | 9 mg | 10 mg |
Best plant-based sources of iron
| Food | Serving size | Iron content |
| Grains, beans & legumes | ||
| Chickpea (besan) flour | 100 g | 8.3 mg |
| Amaranth grain, uncooked | 61 g (1/4 cup) | 4.6 mg |
| Muesli, raw, unfortified | 50 g | 3.8 mg |
| Tofu, firm | 100 g | 2.9 mg |
| Chickpeas, canned, uncooked | 100 g (1/2 cup) | 2.8 mg |
| Quinoa, uncooked | 180 g (1 cup) | 2.7 mg |
| Tempeh | 100 g | 2.7 mg |
| Adzuki beans, cooked | 1/2 cup | 2.3 mg |
| Red kidney beans, canned, uncooked | 100 g (1/2 cup) | 2.1 mg |
| Navy (haricot) beans, cooked | 100 g (1/2 cup) | 2.1 mg |
| Lentils, cooked | 100 g (1/2 cup) | 2 mg |
| Teff, uncooked | 25 g (1/4 cup) | 1.9 mg |
| Oats, rolled, raw | 50 g (1/2 cup) | 1.8 mg |
| Black beans, cooked | 100 g (1/2 cup) | 1.8 mg |
| Tofu, silken or soft | 100 g | 1.8 mg |
| Broad beans, cooked | 100 g (1/2 cup) | 1.7 mg |
| Cannellini beans, canned, uncooked | 100 g (1/2 cup) | 1.6 mg |
| Pinto beans | 100 g (1/2 cup) | 1.4 mg |
| Buckwheat groats, raw | 50 g | 1.2 mg |
| Split peas, cooked | 100 g (1/2 cup) | 1 mg |
| Oats, rolled, cooked | 100 g | 0.9 mg |
| Miso paste | 36 g (2 tbsp) | 0.9 mg |
| Dairy alternatives | ||
| Coconut milk, canned | 125 ml (1/2 cup) | 3.7 mg |
| Almond milk | 200 ml | 1 mg |
| Herbs, spices & condiments | ||
| Dried yeast flakes | 100 g | 3.5 mg |
| Blackstrap molasses | 20 g (1 tbsp) | 3.5 mg |
| Cinnamon | 2.3 g (1 tsp) | 2 mg |
| Curry powder | 4 g (2 tsp) | 1.1 mg |
| Food | Serving size | Iron content |
| Nuts & seeds, raw | ||
| Pumpkin seeds (pepitas) | 30 g (1/4 cup) | 3 mg |
| Chia seeds | 30 g (1/4 cup) | 2.3 mg |
| Tahini, unhulled | 36 g (2 tbsp) | 1.8 mg |
| Coconut, desiccated | 100 g | 1.7 mg |
| White sesame seeds | 30 g (1/4 cup) | 1.5 mg |
| Cashews | 30 g (1/4 cup) | 1.5 mg |
| Sunflower seeds | 30 g (1/4 cup) | 1.4 mg |
| Pine nuts | 30 g (1/4 cup) | 1.2 mg |
| Almonds, skin on | 30 g (1/4 cup) | 1.1 mg |
| Pistachio | 30 g (1/4 cup) | 1.1 mg |
| Hazelnuts | 30 g (1/4 cup) | 0.9 mg |
| Walnuts | 30 g (1/4 cup) | 0.7 mg |
| Pecans | 30 g (1/4 cup) | 0.7 mg |
| Brazil nuts | 30 g (1/4 cup) | 0.6 mg |
| Vegetables | ||
| Sun-dried tomatoes | 100 g | 5.6 mg |
| Spinach | 100 g | 3.5 mg |
| Silverbeet, cooked | 100 g | 2.5 mg |
| Kale | 1 cup | 2.5 mg |
| Swiss chard | 1 cup | 2.3 mg |
| Bok choy, cooked | 100 g | 2 mg |
| Olives, green or black | 100 g | 1.7 mg |
| Green peas, cooked | 100 g | 1.1 mg |
| Asparagus, cooked | 100 g | 1.1 mg |
| Green beans, cooked | 100 g | 1.1 mg |
| Fruit | ||
| Apricot, dried | 30 g (5 pieces) | 0.9 mg |
| Medjool dates, dried, pitted | 30 g (2 dates) | 0.8 mg |
As well as the foods above, fresh herbs and spices such as garlic, basil, ginger, chives, coriander, parsley and oregano are all rich sources of iron, so add them to your meals.
How to maximise iron absorption
Increasing your intake of iron-rich foods is not the only way to boost your iron levels.
Plant-based iron vs animal-based iron
There are two types of iron found in the food we eat, haem iron and non-haem iron. Plants contain only non-haem iron, while animal products (such as meat, fish, poultry, eggs) contain both non-haem and haem iron. Non-haem iron absorption is regulated by the body’s need for iron, meaning it will be more readily absorbed when the body’s in need. Non-haem iron is also more sensitive to dietary factors that either inhibit or enhance absorption.
To increase your iron absorption, follow these guidelines:
- Soak or sprout beans, legumes, rice, grains nuts and seeds – These foods contain phytates (or physic acid) which can inhibit iron absorption. Soaking or sprouting hydrolyses the phytates. Nutrition Stripped has a useful guide for soaking and sprouting.
- Include vitamin C-rich foods with iron-rich foods – Vitamin C reduces the inhibitory effects of phytates and enhances the bioavailability of iron, meaning your body can absorb it better. Vegans and vegetarians will often consume more vitamin C since a plant-based diet usually contains more fruits and vegetables. Some plant foods high in vitamin C include red and green capsicum, broccoli, oranges, and kiwifruit.
- Avoid drinking tea, coffee, red wine and cocoa with meals – Tea (including herbal), coffee (even decaf), red wine and cocoa-based drinks (such as hot chocolates) contain polyphenols, which can inhibit iron absorption.
- Separate your calcium or zinc supplements from your iron-rich meal or iron supplement – Minerals, such iron, zinc and calcium, compete for absorption.
- Cast-iron pans/skillets – Cooking your foods in a cast iron pan can increase the iron content of your food, especially if you are cooking vitamin C-rich foods.
References:
- Iron, Nutrient Reference Values, https://www.nrv.gov.au/nutrients/iron
- Foods that contain Iron (FE), Food Standards Australia and New Zealand, http://www.foodstandards.gov.au/science/monitoringnutrients/nutrientables/nuttab/Pages/default.aspx
- Iron and vegetarian diets, https://www.mja.com.au/system/files/issues/196_10_040612_supplement/sau11494_fm.pdf
- Australian Bureau of Statistics. Australian Health Survey: Usual Nutrient Intakes, 2011-12, http://www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/4364.0.55.008~2011-12~Main%20Features~Iron~402
- Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets, https://www.vrg.org/nutrition/2003_ADA_position_paper.pdf
- EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non-meat-eaters in the UK, https://doi.org/10.1079/PHN2002430
- Hemochromatosis, Mayo Clinic, https://www.mayoclinic.org/diseases-conditions/hemochromatosis/symptoms-causes/syc-20351443
- Dietary intake and nutritional status of young vegans and omnivores in Sweden,
https://www.ncbi.nlm.nih.gov/pubmed/12081822 - Oxalic acid does not influence non-haem iron absorption in humans: a comparison of kale and spinach meals, https://www.nature.com/articles/1602721.pdf
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