We've all experienced it: you've gotten a week's worth of solid sleep and woken up feeling even groggier than before.
There are many possible reasons for fatigue -- from lack of physical activity and poor diet to stress and underlying mental health issues -- and one contributor is something we often overlook: iron deficiency.
To understand more about iron deficiency (and what we can do to help), The Huffington Post Australia spoke to three health experts.
"Iron is an essential mineral that is involved in transporting oxygen throughout the body," body science expert Moodi Dennaoui, aka The Diet Doctor, told HuffPost Australia.
"If you don't have enough iron, your body can't make enough healthy oxygen-carrying red blood cells."
According to dietitian and sports nutritionist, Robbie Clark, iron is essential for providing energy for daily activity and life. Here are the four main roles of iron in the body:
1. Oxygen transport
"Red blood cells contain haemoglobin, a complex protein that carries oxygen from the lungs to the rest of the body. Haemoglobin is partly made from iron and accounts for about two-thirds of the body's iron," Clark told HuffPost Australia.
"Myoglobin is a special protein that helps store oxygen in muscle cells," Clark explained.
"Myoglobin contains iron and is responsible for the red colour of our muscle, plus provide oxygen to them to assist with energy production."
Enzymes are biological proteins which speed up the rate of chemical reactions taking place within our cells, and are vital for life and bodily functions like digestion and metabolism.
"Many enzymes throughout the body contain iron, including those involved in energy production," Clark said. "Enzymes are important as they act as catalysts for many cell functions."
4. Immune system
"[Iron] also plays a big part in our immunity, so if we're low in iron, we may get sick more easily," accredited practising dietitian, Jemma O'Hanlon, told HuffPost Australia.
"Proper functioning of the immune system relies, in part, on sufficient amounts of iron," Clark added.
When we become low in iron, there are common signs and symptoms telling us we're in need of the mineral. These signs are mostly reflected in our energy levels, as well as our concentration and skin colour.
"Iron deficiency is caused by a depletion of iron stores which may result in a decrease in the levels of haemoglobin in the blood. Low iron levels may lead to a condition called iron deficiency anaemia, which is a result of low ferritin levels," Clark said.
Common symptoms of iron deficiency anaemia include:
- Tiredness and lethargy
- Breathlessness (even when you're not exerting yourself)
- Loss of appetite
- Pale complexion
- Heart palpitations
- Hair loss or thinning
- Lack of concentration
- Increased risk of infection
- Weakness and/or dizziness
One of the first symptoms you can experience when iron deficient is fatigue.
"Without healthy red blood cells, your body can't get enough oxygen and so the immediate symptom of a lack of iron is fatigue," Dennaoui explained.
"The word 'fatigue' is very broad and can mean a number of things -- a lack or slowing down of brain function, or a reduction in your body's immune system's ability to fight off infections."
Iron deficiency can also affect your body's strength and exercise performance, as well as the health of your hair and skin.
"Cardiovascular performance decreases, as does strength and muscle endurance, as they are all physiological processes that require healthy red blood cells," Clark said. "Iron is also necessary to maintain healthy cells, skin, hair, and nails."
According to O'Hanlon, women need to be extra cautious of iron deficiency as they lose iron through menstruation.
"Young women are at a greater risk of being low in iron, so it's important that if you're feeling a little flat that you get a check up with your GP," O'Hanlon said.
"Women in their reproductive years have a much higher iron requirement than men due to the loss of monthly blood. As such, they can find it difficult to meet their daily requirements with food alone, which means they also have a higher risk of iron deficiency," Dennaoui added.
If you experienced any of the above symptoms, all three health experts strongly recommend heading to your GP to get your iron levels tested.
"If you have been complaining about tiredness or fatigue for a while, or have been expressing any of the symptoms mentioned above, then it could be worth your while to see your GP and get some general bloods done and investigate your iron levels," Clark said.
"A dietitian or GP can interpret your bloods and inform you whether your levels warrant supplementation."
Some population groups who may require an iron supplementation due to being at risk for iron deficiency include:
- Teenage girls
- Menstruating women, particularly those with heavy periods
- Vegetarians and vegans
- Athletes, particularly female athletes
- Those with inflammatory bowel disease or coeliac disease
- Regular blood donors
- Those with chronic diseases such as cancer, kidney disease, heart failure, autoimmune diseases
- People with poor diets, restricted diets or following fad diets
To help assist in iron deficiency, and to avoid it altogether, ensure you are including a variety of iron-rich foods.
"There are two types of dietary iron: haem iron (found in animal foods only) and non-haem iron (found in eggs and plant foods)," Clark said.
Rich sources of haem iron include:
- Red meat (beef, kangaroo, lamb)
- Offal (internal organs of animals such as liver)
- Chicken (chicken liver, in particular)
Rich sources of non-haem iron include:
- Whole eggs (iron is found in the yolk)
- Legumes (such as lentils and chickpeas)
- Dark leafy greens (such as spinach)
- Pumpkin seeds
- Raw cacao or dark chocolate
- Whole grains (such as barley and brown rice)
"Lean red meat is the best source of iron. Chicken, pork and fish are also good sources," O'Hanlon said.
"Contrary to popular belief, we absorb much less iron from plant foods such as spinach and broccoli, and although these are extraordinarily healthy foods, we should be eating these more for their folate than for their iron."
It's also important to note that there are dietary factors that boost and reduce iron absorption.
"Vitamin C is an iron enhancer," Clark said. "Foods rich in vitamin C can greatly boost the absorption of non-haem iron. Foods such as citrus fruits and juices, strawberries, kiwi fruit, pawpaw, melons, green leafy vegetables, capsicum, tomato and broccoli are great to add to meals to ensure the best uptake of iron."
"Soy proteins can reduce absorption from plant sources," Clark added. "Calcium and phosphorus reduce the absorption of plant based sources of iron."
The recommended dietary intake (RDI) for iron is different for different population groups. An outline of these can be seen below:
Age -- RDI
- All 1-3 years -- 9mg per day
- All 4-8 -- 10mg per day
- Girls 9-13 -- 8mg per day
- Girls 14–18 -- 15mg per day
- Boys 9-13 -- 8mg per day
- Boys 14–18 -- 11mg per day
- Females 19–50 -- 18mg per day
- Female 51+ -- 8mg per day
- Males 19+ -- 8mg per day
- All pregnant women -- 27mg per day
- Lactating women 19–30 -- 9mg per day
"In most cases, it is quite easy to meet your recommended daily intake for iron," Clark said.
To put these recommended daily intake digits into a real life situation, here are some examples of foods and their iron content.
Haem iron sources:
- 100g chicken liver = 11mg
- 100g beef steak = 3.5mg
- 100g kangaroo meat = 3.2mg
- 100g salmon fillet = 1.28mg
- 100g chicken breast = 0.4mg
- 30g Weetbix = 4.2mg
- 1 cup lentils = 3.7mg
- 1 cup kidney beans = 3.1mg
- 100g tofu = 2.96mg
- 1 cup cooked quinoa = 2.8mg
- 1 cup chickpeas = 2.7mg
- 1 cup cooked rolled oats = 1.3mg
- 1 cup raw spinach = 1.2mg
- 1 slice wholegrain bread = 0.8mg
- 1 whole egg, boiled (45g) = 0.7mg
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