Tried of feeling tired? Here’s how to increase iron absorption in your diet

Written by Associate Nutritionist Spela Horjak.

Iron deficiency is the most common form of nutrient deficiency globally. According to the World Health Organization (WHO), iron deficiency anemia affects 30% of women between the ages 15-49 and 40% of children between 6-59 months of age.

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The role of iron in the body

Iron is an essential mineral for human life, which is involved in the creation of haemoglobin, a protein in red blood cells that carries oxygen from the lungs to the rest of the body. Iron is also needed to produce myoglobin, a protein found in the heart and skeletal muscles that stores oxygen in muscles and is thus involved in muscle metabolism. All tissues require oxygen to survive so iron is also essential for physical growth and neurological development, and the synthesis of certain hormones. Iron deficiency can impact the physical and cognitive development of children (iron requirements increase during rapid growth spurts) and the productivity levels of adults.

Haem and Non Haem Iron

Because iron isn’t produced in the body, we need to obtain it from food. Iron is naturally present in some foods, added to others through fortification, and also available as a supplement.

Haem iron is found only in animal foods, such as red meat, liver, kidney, poultry and fish like sardines and pilchards. While red meat is a good source of iron, the recommended daily amount is no more than 70g of red meat per day.

Non haem iron is found in both animal foods i.e. eggs and dairy and plants like beans & pulses, nuts & seeds, dark-green leafy vegetables, tofu, hummus, tahini, dried fruit like apricots, raisins and prunes, and fortified cereals & bread.

We should be able to get enough iron through a balanced diet that is well-planned, but sometimes supplements may be used to increase the levels in case of severe deficiencies. It’s important not to take more iron than is recommended as excess iron may cause nausea, stomach pain and/or constipation.

Haem iron is generally better absorbed than non-haem iron. This doesn’t mean that those following a vegan or vegetarian diet can’t obtain enough iron from plant sources. A well-planned and varied plant-based diet should provide enough iron.

Iron requirements

The amount of daily iron requirement will vary by gender and stage of life. Please see this handy breakdown of iron requirements for different population groups:

	Age Group	Daily Iron Requirements (mg)
Females	11-49 years	14.8
	Pre menopausal women	14.8
	Post menopaousal women	8.7
Males	11-18 years	11.3
	19+	8.7

Iron Deficiency Anemia

Iron is stored in the liver, bone marrow, and spleen for later use, so short-term low intake of iron isn’t a problem since the body dips into its stores when necessary. It’s only when these stores become low/depleted that this may result in a condition called iron deficiency anaemia. This condition is characterised by low haemoglobin levels, a slower rate at which new red blood cells are created, and existing red blood cells becoming smaller, which all contribute to lower blood quality.

Anaemia in the short term may manifest as:

• Tiredness
• Weakness
• shortness of breath
• dizziness

Anaemia in the long term may manifest as:

• an increased risk of infections (because iron is involved in the immune system)
• heart and/or lung problems
• restless leg syndrome
• pregnancy complications
• brittle nails, thinning hair, itchy skin or mouth ulcers.

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Iron Rich Foods

Non Haem Iron

Food	Portion	Iron content (mg)
Weetabix	2 biscuits	4.5
Shredded wheat	40g	3.1
Lentils (cooked)	100g	3.0
Tofu	100g	5.0
Spinach	100g	2.5
Dark chocolate	25g	2.0
Kidney beans	100g	2.0
Chickpeas	100g	2.0
Potato with skin	Medium	1.5
Quinoa (cooked)	100g	1.5
Pistachios	30g	1.0
Rye bread	1 slice	1.0
Dried apricots	30g	0.8
White button mushrooms	100g	0.5

Haem Iron

Food	Portion	Iron content (mg)
Chicken liver	100g	14.0
Oyster	100g	4.0
Mussels	100g	3.5
Cooked beef	100g	3.5
Canned sardines	100g	3.0
Chicken thigh	100g	1.0
Eggs	1 large	0.6

How to increase Iron absorption

There are several factors increasing iron absorption:

• The presence of vitamin C increases iron absorption. A good rule of thumb is to ensure that each meal contains a source of fruit of vegetables because most fresh produce contains vitamin C. Especially high sources of vitamin C are citrus fruits, peppers, tomatoes, berries, brussels sprouts, cabbage, papaya, oranges, and potatoes.
• The inclusion of animal protein increases the absorption of non-haem iron from plant foods (referred to as “the meat factor” – for example, adding sardines to your avocado on wholegrain toast or chicken to your chickpea curry; the same cannot be said for eggs which have been shown to hinder the absorption of non-haem iron
• Phytates in iron-rich foods like beans, lentils, and wholegrains contribute to low iron availability in those foods – this can be overcome by soaking those foods and discarding the water prior to cooking.

What hinders the absorption of iron

There are several factors impacting iron absorption:

• The use of proton-pump inhibitors (medication decreasing stomach acid) will impact the absorption of iron. This is relevant for people with iron deficiency, while the short-term use of PPIs won’t affect people with normal iron stores
• The inclusion of unprocessed wheat bran in meals (as a way of increasing fibre) will hinder the absorption of iron due to compounds called phytates. This can be counteracted by including a source of vitamin C in the meal
• Tea & coffee contain compounds called polyphenols which reduce iron absorption, so make sure you leave at least an hour between your iron-rich meal and your hot drink. The same goes for chocolate and fizzy drinks containing caffeine like Coca-Cola
• There’s some research to show that calcium supplements may hinder the absorption of iron so if you take calcium supplements, make sure you take them at different times than iron supplements

Iron and our genes

Research shows that the iron status in an individual is influenced by a combination of genetics, dietary and lifestyle factors. For example, several genes can impact the risk of having low iron status, including TMPRSS6, Transferrin Teceptor 2 and Transferrin.

For example, The TMPRSS6 gene provides instructions for making a protein called matriptase-2. This protein is part of a signaling pathway that controls the levels of another protein called hepcidin, which is a key regulator of iron balance in the body. When blood iron levels are low, this signaling pathway reduces hepcidin production, allowing more iron from the diet to be absorbed through the intestines and transported out of storage sites into the bloodstream. Any variations in the TMPRSS6 gene can alter this feedback loop between matripase-2 and hepcidin, causing a higher risk of iron deficiency in some people. This highlights the impact our genes have on our nutritional status. Nishti explains more about iron and genetics in this video.

Here at Nishti’s Choice, we provide genetic testing analysis which helps to determine your risk for low iron status. Is it not a blood test! The test is very non-invasive (mouth swab) and provides you with details about the above-mentioned genes. To hear more or to book a no-obligation chat please visit the booking page.

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Pichler, Irene et al. “Identification of a common variant in the TFR2 gene implicated in the physiological regulation of serum iron levels.” Human molecular genetics vol. 20,6 (2011): 1232-40.