“Beauty is an iron mine,” Australian mining magnate Gina Reinhart once said. She was talking about a precious resource, but iron is so important to living organisms: from bacteria and fungi, to mammals like us.
Iron plays a key role in many metabolic processes in our body. But iron deficiency is one of the major global health risks identified by the World Health Organization (WHO).
Iron deficiency is the most prevalent micronutrient disorder worldwide, and COVID may exacerbate the problem.
Iron is hard to come by
The type of iron we mine is different from biologically usable “free-form” iron. Free-form iron has a tendency to jump between two chemical states, allowing it to bind to various molecules and participate in all kinds of essential reactions in our body.
But again we see a different story during food digestion. Iron is absorbed most efficiently in our upper small intestine, where free-form iron binds to oxygen, other minerals, and food components. This usually results in rock-like, insoluble clumps (those are the ones we mine!). These are too large to pass through or between our cells.
This means that even when we consume enough iron, typically only ~15-35% of it is absorbed. This means iron availability can be improved or inhibited by how we eat it or what we eat.
For example, heme iron from animal meat has a cage-like structure that carries the iron in a soluble form that prevents it from sticking during absorption. In many Western countries, heme iron accounts for only 10% of dietary iron, but accounts for two-thirds of total iron absorption.
Most of us are at risk of deficiency
Getting enough iron sounds like simple math: we want add Our dietary intake is sufficient to compensate for the iron content lost From the body, for example through faeces, skin shedding, menstruation (for women) and sweat. But the two sides of the equation can change depending on who and where we are in our lifetime.
Generally, iron deficiency occurs when our body’s iron stores are depleted because we are not consuming or absorbing enough iron to meet our needs.
This can happen when people restrict their diet for religious, social or medical reasons. Some people have a harder time when their need for iron increases, such as pregnant women and growing children.
But iron deficiency can occur when the body has enough iron, but cannot efficiently transport it into the cells. It is common in people with acute and chronic infections, heart and autoimmune conditions, and cancer. In these cases, the underlying disease should be treated first rather than improving iron intake.
The table below summarizes some of the most common causes of iron deficiency. Sometimes multiple causes can occur simultaneously – for example, for many elite athletes (35% of women and 11% of men), iron deficiency is caused by reduced absorption due to inflammation, on top of increased loss through sweat and blood cell breakdown.
COVID didn’t help
The ongoing COVID pandemic has introduced many risk factors for iron deficiency.
Acute infection with SARS-CoV-2 (the virus that causes COVID-19) can change the way some people metabolize iron, leading to low iron levels for up to two months after infection. This contributes to symptoms commonly reported after infection, such as fatigue and lethargy.
Recovery from the pandemic has exacerbated food supply problems, as well as increasing global income inequality.
This means more people face barriers to food security – and nutrient-dense foods that help increase our iron intake, such as red meat or leafy greens, are either unavailable or unaffordable.
Read more: Why we need to take a woman-centered approach to diagnosing and treating iron deficiency
Before you take the pill
It can be tempting to take one of the widely available iron supplements to try to increase your intake. However, we must keep in mind that traditional iron supplementation is associated with some negative side effects.
These include damage to the lining of our intestines, nausea, diarrhea and constipation. Iron supplementation is associated with changes in gut microbiota, a critical determinant of health.
WHO recommends two other approaches: dietary diversification and dietary fortification.
Dietary diversity is just what it sounds like: having a diet with a variety of whole foods like fruits and vegetables, whole grains and legumes, meat, dairy, and nuts and seeds.
This approach not only ensures adequate amounts of iron in the foods we eat, but also that they come in different forms or “vehicles” to improve absorption. This method also works with plant-based foods.
Read more: What to drink with dinner (and what to avoid) to get more iron from your diet
Food fortification that adds iron to processed foods is a fairly safe and accessible option due to its low dosage. In Australia, iron is commonly fortified in products such as bread, cereals and ready-to-drink mixes.
It can be challenging to get iron into our bodies and where it is needed. But before turning to supplements, we must remember that food sources should always come first. In cases of diagnosed deficiencies, your healthcare professional will provide you with more information on where supplements are needed.
Read more: Lemon water won’t detoxify or energize you. But it can affect your body in other ways