Iron deficiency is the most common and widespread nutrient deficiency worldwide. It is the most common cause of anaemia and affects 2 billion people globally. Anaemia occurs when there is a reduction in either the total amount of red blood cells, or a reduction in haemaglobin (the protein which gives blood it’s red colour and transports oxygen from the lungs to the rest of the body), which deprives the body of oxygen. Anaemia can also be caused by a B12 or folate deficiency, but iron deficiency anaemia is most common.
Plant-based VS animal products
Our bodies do not produce iron, therefore it must be obtained solely from our diet. And whilst iron is widely distributed in food, absorption rates vary broadly depending on the food source. There are two types of iron: haem iron (found in meat) and non-haem iron (found in dairy and plants). Haem iron is much better absorbed than non-haem iron, but there are a few tricks of the trade to maximise absorption of plant-based irons.
One of the biggest things to consider when trying to increase absorption of non-haem/plant-based iron is to add vitamin C to the plant-based iron source. This maximises the bioavailability of non-haem iron and increases its absorption significantly. So adding a cut up orange to your lentil salad, or drizzling the juice of a whole lemon all over your green veggies will maximise your bodies’ ability to absorb plant-based iron.
How much iron do we need?
The Recommended Daily Intake (RDI) for iron is 8mg/day for men, 18mg/day for menstruating women, and 27mg/day during pregnancy, as set by the National Health and Medical Research Council (NHMRC) and the Australian Government Department of Health.
Women have greater iron needs than men, due to monthly losses through menstrual blood. Women with menorrhagia (abnormally heavy menstruation) may have even higher iron demands, however excessive bleeding should be investigated by your healthcare practitioner to determine and treat the underlying cause. Women taking the oral contraceptive pill may have a lesser need for iron as their periods are generally lighter. They may choose to skip their period some months (more on this another time) meaning no iron is lost in a bleed, however they should still be aiming to meet the RDI of dietary iron.
The bodies’ need for iron increases dramatically during pregnancy as blood volume expands and a baby with its own blood supply is created. Iron deficiency during pregnancy is heavily linked with postpartum depression and can have severe consequences for the baby including premature birth and low birth-weight, so it is essential to monitor iron levels prior to conception as well as during and after pregnancy.
What are the symptoms of iron deficiency?
Any or all of the following can be indicative of low iron levels*:
- General fatigue
- Lowered immunity
- Shortness of breath
- Depression (iron is required for the synthesis of hormones and neurotransmitters such as serotonin – our happy chemical)
- Cold or tingling hands and feet
- Behavioural changes in children, including hyperactivity
- Tongue swelling or soreness
- Cracks/inflammation on the corners of the mouth
- Digestive upsets including constipation
- Pica (strong desires to eat non-food items such as clay, dirt, ice, hair etc)
- Fast or irregular heart beat
- Brittle hair or nails
- Easy bruising
- Paleness of skin, gums and lower eyelids
- Spoon-shaped nails
- Pale lines on stretched palms (palmar creases)
- Light or heavy menstrual flow
- Redness and inflammation of the tongue
- Night cramps
- Cardiac failure
*Please note: the above signs and symptoms can also be indicative of other nutrient deficiencies and/or health conditions. Iron deficiency should not be assumed without a blood test, and supplementation should not be commenced without advice from a healthcare practitioner, in order to help assess the best dosage and form of iron for your individual requirements. Taking iron supplements when they are not required can be harmful, this is why all iron supplements are in child-resistant packaging. Fatigue, although commonly thought to be a sign of low iron, is indicative of many things including iron levels which are too high (yes, you read that correctly – a condition called Haemochromatosis – an inherited iron overload disorder). The body will also “hide” iron during an acute infection or inflammation, but other indicators of this will also show on a general blood test, and the correct treatment in these instances may not be iron supplementation, even if iron levels appear low. Hence, blood tests are essential to identify iron levels and other possible causes of symptoms, prior to supplementation.
Which foods contain iron?
- Legumes i.e. lentils and chickpeas
- Green leafy veggies (be sure to cook spinach and kale to reduce oxalic acid which actually decreases iron absorption)
- Whole grains
- Organic soybeans i.e. tofu and tempeh
- Red meat
- Organ meats (liver)
Does anything reduce the absorption of iron?
- Polyphenols/tannins found in chocolate, coffee and tea (including many herbal teas) bind to minerals such as iron in the gastrointestinal tract and prevent its absorption
- Oxalates found in tea as well as spinach, parsley, rhubarb and kale (cooking these foods reduces oxalates) bind to minerals such as iron in the gastrointestinal tract and prevent its absorption
- Phytic acid found in whole-grains and legumes (soaking these foods reduces their phytate content) bind to minerals such as iron in the gastrointestinal tract and prevent its absorption
- Other divalent cations i.e. calcium, zinc, phosphorus and manganese (if trying to increase iron levels, consume dairy products at least 1/2 an hour away from iron-rich foods, and take supplements containing these minerals at least 2 hours away from iron supplements/food sources)
- Phosvitin – a protein found in egg yolks
- Digestive issues including parasites and inflammatory bowel conditions (speak to your healthcare practitioner about rectifying any digestive issues you may be experiencing)
- Certain medications including antacids for reflux (these also decrease absorption of other nutrients such as calcium, B12, folate and zinc)
To sum up…
So we know now that if we are trying to increase our intake of iron then adding vitamin C rich foods such as kiwi fruit, citrus and pineapple to our non-haem/plant-based iron sources can increase bioavailability and absorption significantly. And we know that we should not be adding raw kale and spinach to our meals if we are relying on them as primary sources of iron, as the oxalates bind to iron and hinder absorption – instead these foods need to be lightly blanched prior to eating. And we also know that we need to drink our sweet delicious coffee and tea two hours before and after our meals and iron supplements in order to maximise mineral absorption. And to get the best nutritional “bang for our buck”, we want to soak our grains to reduce the phytic acid content which binds to minerals such as iron and prevents it being absorbed. Green vegetables such as broccoli and bok choy are both heroes in the iron world as they contain non-haem iron but also ample amounts of vitamin C to enhance absorption, as well as a plethora of other health promoting vitamins, minerals and phytochemicals. Small considerations such as snacking on figs or adding prunes to your breakfast can also add to your daily intake of iron. And if you’re thinking about having a baby, then a preconception check-up including blood tests will help you assess your iron levels and the potential need to increase them, to ensure the best outcome for both Mum and baby – pre, peri, and postnatal.