Iron: The Essential Mineral for Life

According to an article published in The Lancet, iron deficiency anaemia affects 33% of the world’s population. It’s a crucial nutritional element at any age. However preschool-age children, women of childbearing age and pregnant women need more of it. Also, vegetarian and vegan groups need to monitor their iron intake as well. 

Let’s look at what exactly iron is and does in the body and how you can boost your intake. Also, If you want to know what an iron studies test is and whether or not to take iron supplements, keep on reading.

What Is Iron?

Iron is an essential mineral that’s involved in energy production, DNA synthesis and oxygen transport to the brain and body. Iron is a chemical element found in all living organisms. The iron in your body is the same type of iron found in iron ore. However, in the diet, there are two types of iron that can be obtained: haeme and non-haeme iron. 

Haeme & Non-Haeme Iron

Haeme iron is the type of iron found in meat and animal products and is used readily in the human body. Haeme is physiologically important and differs from non-haeme iron. Non-haeme is unbound and is found in plants and vegetables. The body absorbs and utilises haeme iron at a much higher rate than non-haeme iron. Essentially, how much animal protein you’re consuming will be a determining factor in your overall iron status and risk for iron deficiency.

So the question is, does a vegetarian or vegan diet sufficiency contain enough iron? Well, some research suggests that to make up the difference in haeme versus non-haeme iron foods, vegetarians need to consume almost double the amount of iron from plants compared to non-vegetarians. A mixed diet of foods from land, earth and sea will always be my preference to promote optimal health. In the case of non-meat eaters, it’s not impossible to maintain adequate iron levels. However, over the long term and in certain aspects of life, it can become quite challenging.

The Role of Iron In the Body

Iron metabolism is a tightly controlled process in the body. Iron absorption occurs in a part of the small intestine called the duodenum. When the body is replete with iron, a hormone called hepcidin switches on and blocks dietary iron absorption. What’s leftover is stored in the liver for later use.

Oxygen Transportation

Probably the most important role of iron is in the blood and circulatory system. Red blood cells, which transport oxygen throughout the body, contain a protein called haemoglobin. This compound has a haeme molecule at its centre and represents around 67% of the body’s iron supply. Haeme iron is also a component of myoglobin, a protein that carries oxygen to the muscles. Iron is essential for hormones, cell activity and nervous system development. 

Chemical Signalling

Other than oxygen transport, haeme iron also plays an important role in chemical signalling, enzyme reactions, and DNA synthesis. Haeme iron also helps make serotonin. The brain needs to be well oxygenated, and as such, adequate iron levels become fairly important. In fact, studies have shown that low iron is linked to cognitive impairment and neurodegeneration. 

Immune System

The human body and our immune system is remarkably clever, as we’ve seen over and again. Like zinc, iron is used by bacteria for replication. In situations of infection in the body, plasma concentrations of iron are lowered. Then, once there’s enough inflammation, hepcidin kicks in and sequesters iron away. This is termed a ‘functional iron deficiency and is a protective mechanism of the body.

The goal here is to stop invading bacteria from using the body’s iron to replicate and grow. Once the infection and associated inflammation have subsided, this iron deficiency state will self-resolve. However, in situations of chronic or recurrent infections, iron deficiency can continue resulting in various health issues. 

Recommended Daily Intake of Iron

Different life stages and demands will call for different levels of iron intake. And, it’s not a simple upward curve, as outlined below. Babies need more iron than children, and adolescent girls need more iron than adolescent boys. 

Nowadays, the RDI for iron caters to the prevention of iron deficiency and maintenance of iron stores. To this end, the current recommendations are as follows:

• Infants (Up to 6 mo): 0.27 mg/day
• Babies (6-12 mo): 11 mg/day
• Children (1-3y): 7 mg/day
• Children (4-8y): 10mg/day
• Children (9-13y): 8mg/day
• Adolescent boys (14-18y): 11 mg/day
• Adolescent girls (14-18y): 15 mg/day
• Adult men: 8 mg/day
• Adult women: 18 mg/day
• Women over 50yrs: 8 mg/day
• Pregnancy: 25 mg/day
• Breastfeeding: 10-15 mg/day

How do you know if you’re getting enough iron?

If you’re enjoying a range of healthy foods, including meat and seafood, you’re more than likely going to be replete with iron. However, if you’ve recently been unwell, have had a baby, have heavy menstrual cycles or are vegan, chances are that you could be low in iron. 

Aside from getting a blood test, how do you know if you need to up your iron intake? One obvious symptom of iron deficiency is fatigue. If you’re flat-out tired and it seems relentless, it’s worthwhile getting your iron checked. Another classically related symptom is depression. Feeling low in energy with low mood and low motivation can mean your iron levels need a checkup.

Common Symptoms of Iron Deficiency Anaemia

• Fatigue
• Irregular heartbeat
• Cold hands and feet
• Mood disturbances
• Lightheadedness
• Irritability
• Weakness
• Pallor & brittle nails
• Chronic or recurrent infections

Obviously, these clinical signs can be due to many other health issues. It’s always best to work with a trusted health provider to understand what’s going on and how best to help. 

Ruling out any major problems and determining if your iron levels are okay or not, provides a pathway to improving your health.

Food Sources of Iron

Food	Amount of Iron
250g beef	1.6 mg
2 or 3 chicken livers	3.6 mg
1 tablespoons prunes	1 mg
1 box sultanas	.8 mg
Baked potato	1.8 mg
1 cup cooked spinach	6.4 mg
1/2 cup cooked white beans	3.3 mg
1/2 cup tofu	6.6 mg
1 tablespoon hazelnuts	1.3 mg
1 tablespoon cashews	1.9 mg

(Source: Linus Pauling Institute, 2022)

Iron-Rich Snacks & Meals

If you need more dietary iron, just add some iron-rich foods as snacks and at mealtimes. 

• Baked beans with multigrain sourdough 
• Chicken liver pate with carrot sticks
• Loaded spud with savoury mince, chives and sour cream
• Quinoa and spinach salad with roasted sweet potato, chopped hazelnuts and orange tahini dressing
• Rib fillet steak, wilted spinach, grilled tomato and baked potato

Did you know?

• Citrus (vitamin C) with any iron-rich food will enhance iron absorption
• Coffee, tea and red wine (tannins) will inhibit iron absorption

Does Cast-Iron Cookware Help Anaemia?

Do you cook with cast iron pans, pots and dutch ovens? 

This may not be a well-known fact, but cast-iron cookware can actually help to boost your daily iron intake.

A 2021 systematic review revealed that cooking with cast-iron improves anaemia in certain populations. In fact, some studies showed iron levels actually doubled. More than two dozen trials were included in this systematic review. The authors concluded that cooking food in iron pots elevated the levels of blood haemoglobin, by increasing the iron content of the food. Essentially, this means a decrease in incidences of iron deficiency anaemia. Interestingly, this review also established that the ‘bioavailability of food containing haeme-iron increases more’ when cooked in cast-iron cookware than food with non-haeme iron. 

What About Iron Supplements or Iron-fortified Foods?

Wherever possible, getting naturally derived iron from food is the best option. The main reason for this is that most synthetic iron supplements and fortified foods contain non-haeme iron. As we’ve discussed, non-haeme iron is difficult to absorb in the digestive system. And some people also experience gastrointestinal discomfort from iron supplements. 

Some higher-quality iron supplements and even herbal medicines contain iron-glycinate or lactoferrin which are bioavailable forms, and are more gentle and more readily absorbed in the body. 

Iron-fortified foods are widely available. Fortified breakfast cereals, bread, baked goods and even baby food all contain non-haeme forms of iron. Unsurprisingly though, it’s often heavily processed, of poor quality and your body doesn’t absorb it well.

If you have a confirmed iron deficiency, it’s always best to work with a health provider who can guide you, rather than guessing with off-the-shelf supplements.

What Does an Iron Studies Test Reveal?

In most countries, iron status can be assessed using laboratory tests that measure different iron markers in a blood sample. The circumstances under which you take an iron test will greatly influence the results. 

So, it’s important to interpret blood tests in the context of your entire health scape. 

For example, if you’ve just had a baby or are recovering from surgery, your iron levels could potentially be low. Likewise, if you’ve had a chronic viral illness or have been on a long-term vegan diet, your stored iron will likely be depleted. 

Here’s a breakdown of what’s measured during an iron studies test and what it means:

Serum iron

This is the free and available amount of iron circulating in the blood (serum). Serum iron can be low due to acute infections or frank iron deficiency. Alternatively, serum iron can be high if you’ve just eaten a huge iron-rich meal. On its own, serum iron doesn’t give you a clear picture of what’s happening with iron in the body. 

Transferrin

Transferrin is a protein molecule that attaches to iron and moves it around the body. Some pathology labs also call this TIBC or total iron binding capacity. Essentially, it’s a measurement of the amount of iron that can be efficiently transported in the blood. It also gives more of an idea of whether the free serum iron can reach its target tissues.

Transferrin Saturation

This is a reading that’s derived from combining the serum iron and transferrin amounts. It’s a percentage figure that represents the amount of iron that’s been attached to transferrin. It’s a more accurate indicator of the available iron in the body and whether it’s being utilised appropriately. Usually, a low serum iron reading will correspond with a low transferrin saturation percentage. This is often a typical indicator of iron deficiency. Whereas, a higher saturation reading can be a sign of iron toxicity or a marker for haemochromatosis. 

Ferritin

Lastly, there’s ferritin. This blood marker is the best measure of stored iron. Ferritin is a protein that attaches to iron and sequesters it away for storage when circulating iron levels have reached repletion. Low ferritin is commonly associated with chronic iron deficiency. It’s not unusual to see low ferritin in postpartum women, due to the high demand that childbearing has on the body. Whereas high ferritin can be caused by liver inflammation and chronic illness.

Enjoy a Balanced Diet and Listen To Your Body

Ensuring you have enough iron in the diet can be easily rectified by varying the diet to include quality red meat, dairy, seafood and vegetables. It’s also important to remember that ameliorating iron in the body takes time. As essential of a mineral as iron is, getting it right is never a one-size-fits-all operation. So if you suspect you have an issue with iron in the diet, it’s best to recruit the help of a professional. And above all, listen to your body’s signs and symptoms.