Iron deficiency is the most common nutritional deficiency in Australia, affecting roughly 1 in 8 people at any given time. It's also one of the most under-recognised: fatigue, brain fog, and shortness of breath are easy to chalk up to a bad week rather than a physiological problem. Yet left untreated, iron deficiency can progress into iron deficiency anaemia, a condition where your blood can no longer carry enough oxygen to meet your body's demands.
What iron actually does in your body
Iron is a mineral your body uses to make haemoglobin, the protein in red blood cells that carries oxygen from your lungs to every other tissue. Without enough iron, red blood cell production drops. Muscles, organs, and the brain all receive less oxygen than they need.
Iron also supports myoglobin, a protein that stores oxygen in muscle tissue. It plays a role in producing certain hormones and maintaining healthy immune function. Your body can't make iron itself. Every milligram has to come from food or supplementation.
Two forms exist in food. Haem iron comes from animal sources (red meat, chicken, fish) and the body absorbs it efficiently, around 15–35% of what's consumed. Non-haem iron comes from plant sources (legumes, spinach, tofu) and the absorption rate is much lower, around 2–20%. That gap matters a lot for vegetarians and vegans.
Who's most at risk
Women of reproductive age carry the highest risk. Menstruation creates a monthly iron loss that diet doesn't always replace, especially if periods are heavy. Pregnancy increases iron demand sharply: the body needs extra iron to support a growing placenta and foetal red blood cell production.
Other high-risk groups include:
- Vegetarians and vegans relying solely on non-haem sources
- Distance runners, where repeated foot-strike causes haemolysis (red blood cell breakdown)
- People with coeliac disease or Crohn's disease, where gut inflammation reduces absorption
- Frequent blood donors
Men aren't exempt. Gastrointestinal blood loss from ulcers or colorectal polyps is a common cause in adult males and warrants investigation. Don't assume low iron is just a dietary problem if you haven't had blood loss ruled out.
Signs that your iron might be low
Fatigue is the most reported symptom. It's often described as a heaviness that sleep doesn't fix. But iron deficiency produces a cluster of signs beyond tiredness:
Pale skin and pale inner eyelids are reliable visual cues. Brittle nails, hair thinning, and a sore or swollen tongue can follow. Some people develop pica, an unusual craving for non-food substances like ice, clay, or starch. Cold hands and feet, frequent headaches, and difficulty concentrating are also consistent with depleted iron stores.
The only way to confirm iron deficiency is a blood test. A full iron studies panel measures serum ferritin (your stored iron), serum iron, transferrin saturation, and haemoglobin. Ferritin is the most sensitive marker: it drops before haemoglobin does, which means you can be symptomatic before you're technically anaemic. Ask your GP for a full iron studies panel, not just a routine full blood count.
How to fix iron deficiency
Treatment depends on severity. Mild deficiency often responds to dietary changes. Moderate to severe deficiency typically requires supplementation, and in some cases intravenous iron infusion.
For dietary improvement, red meat (particularly beef and lamb) delivers the most readily absorbed haem iron per serve. Organ meats like liver are exceptionally iron-dense, though they're high in vitamin A so shouldn't be eaten daily. Canned sardines and oysters are solid options. For plant-based sources, lentils, chickpeas, tofu, pumpkin seeds, and fortified cereals all contribute.
Vitamin C consumed alongside non-haem iron dramatically boosts absorption. A glass of orange juice with a lentil dish, or capsicum added to a tofu stir-fry, makes a real difference. Conversely, tannins in tea and coffee, calcium in dairy, and phytates in raw bran can all inhibit iron absorption if consumed at the same meal. Timing matters.
Oral iron supplements are the standard first-line treatment for confirmed deficiency. Ferrous sulfate is the most common form and is inexpensive. Ferrous gluconate and ferrous bisglycinate are gentler on the stomach. Side effects including constipation and nausea are common; taking iron with food reduces the discomfort, though it also slightly reduces absorption. Some people do better on alternate-day dosing, which research published in the past decade suggests may maintain better absorption than daily dosing due to hepcidin regulation.
IV iron infusion is used when oral iron fails, isn't tolerated, or when stores need to be replenished quickly (post-surgery, late pregnancy, severe anaemia). The infusion typically takes 15–60 minutes and can restore iron stores far faster than oral supplementation. It's available through hospitals and some private clinics across Australia.
How long does it take to recover?
Haemoglobin levels typically start improving within 2–4 weeks of consistent supplementation. Ferritin stores, however, take longer. Most practitioners recommend continuing iron supplementation for 3–6 months after haemoglobin normalises, to fully replenish tissue stores.
Symptoms like fatigue often improve before blood results normalise. Don't stop supplementing early just because you feel better. Get a follow-up blood test at 8–12 weeks to confirm progress.
Iron deficiency that keeps returning despite adequate intake or supplementation needs further investigation. Recurrent deficiency can indicate ongoing blood loss, a malabsorption condition, or, less commonly, a more serious underlying issue. Persistent low ferritin is worth a conversation with a GP, not just a repeat iron tablet prescription.
Good iron intake works best as part of a broader nutritional picture. If you're curious about how other nutrients interact with energy and recovery, the evidence on what omega-3 does for your body is worth understanding alongside iron. And if fatigue and cognitive slowness are your main concerns, it's also useful to know why magnesium deficiency is so common in Australia and how it compounds the problem.