Iron is an essential building block for human life. We need it to make haemoglobin (to carry oxygen), to generate cellular energy (ATP), and to synthesise crucial neurotransmitters like dopamine and serotonin.
So, when you feel constantly fatigued, anxious, and foggy, and your doctor tells you your iron levels are low, the solution seems obvious: Just take more iron.
But for many people—particularly those dealing with chronic stress, trauma, gut issues, or autoimmune conditions—taking oral iron supplements doesn’t seem to help. The exhaustion remains. To understand why, we have to look past the symptom (low iron) and understand a fascinating evolutionary defence mechanism known as Nutritional Immunity.
Nutritional Immunity: The Biological Arms Race
While humans need iron to survive, so do bacteria, pathogens, and cancer cells. In fact, most invading microbes require iron for their core biological processes. Because of this, the human body has evolved to keep “free” circulating iron extremely low.
When you experience an infection, or when your body is in a state of chronic inflammation (which can be triggered by severe psychological stress, trauma, or a dysregulated gut), your immune system sounds an alarm. It releases inflammatory cytokines, particularly one called IL-6.
This alarm triggers your liver to produce a master hormone called Hepcidin. Hepcidin’s primary job is to lock down the body’s iron supply.
The “Lockdown” Effect
Hepcidin acts like a key turning a lock. It binds to the cellular doors (a protein called ferroportin) that normally allow iron into your bloodstream, causing those doors to close and degrade. Iron becomes trapped inside your cells—specifically in your macrophages (immune cells) and enterocytes (gut cells).
The Microbe Counter-Attack
In response to this lockdown, pathogens have evolved siderophores—chemical crowbars with an incredibly high affinity for iron—to steal it back from your tissues. Some bacteria even have specific receptors designed to pirate iron directly from human haemoglobin and transferrin.
The Danger of “Free” Iron: Avoiding Oxidative Stress
Starving pathogens is only half the story. The body also hides iron during inflammation to protect you from yourself.
Iron is highly chemically reactive. When “free” (unbound) iron interacts with inflammatory peroxides in the body, it triggers the Fenton Reaction. This chemical reaction generates highly destructive oxidants called hydroxyl radicals, which can severely damage lipids, proteins, and DNA.
In modern medicine, we now understand that this iron-driven oxidative stress is a major contributor to chronic inflammatory conditions, atherosclerosis, and cellular damage (ferroptosis). By locking iron away in storage proteins (like ferritin), the body is actively preventing widespread tissue damage during periods of high stress.
The Cost of Survival: Anaemia of Inflammation
This brilliant biological defence mechanism creates a very frustrating clinical reality known as Anaemia of Inflammation (or functional iron restriction). You might actually have plenty of iron stored in your tissues, but because of the hepcidin lockdown, your body cannot access it to make red blood cells or neurotransmitters.
This is why taking oral iron tablets often feels useless during periods of high stress or poor gut health. The iron simply passes through you, often causing severe gastrointestinal discomfort, because the “doors” in your gut are firmly locked.
| Blood Marker | True Iron Deficiency | Anaemia of Inflammation |
|---|---|---|
| Ferritin (Iron Storage) | Low The vault is completely empty. |
Normal or High Iron is locked in the vault, unable to be used. |
| Transferrin Saturation (TSAT) | Low Very little iron in the bloodstream. |
Low Very little iron in the bloodstream. |
| CRP (Inflammation Marker) | Normal No systemic alarm bells ringing. |
High The immune system is on high alert. |
The Intravenous (IV) Iron Dilemma: What the Evidence Shows
When oral iron fails and exhaustion sets in, many patients and practitioners turn to Intravenous (IV) Iron infusions. IV iron bypasses the locked doors of the gut and delivers iron directly into the bloodstream. It can be a life-changing, rapid intervention that effectively raises haemoglobin and reduces the need for blood transfusions.
However, from a clinical perspective, pushing high-dose iron into a body that is actively trying to hide it comes with biological nuances. The clinical trial evidence presents a complex picture of benefits versus risks:
- The Infection Question: Because the body hides iron to starve bacteria, adding massive amounts of accessible iron can theoretically feed pathogens. While major trials in controlled environments (like the PIVOTAL trial for dialysis patients) found proactive IV iron to be safe, broad meta-analyses encompassing over 32,000 patients have noted a modest increase in overall infection risk. This is why leading clinical guidelines (such as KDIGO) recommend temporarily pausing IV iron therapies during active systemic infections.
- Feeding the Fire: As mentioned above regarding the Fenton Reaction, infusing large amounts of iron into a highly inflamed system can temporarily worsen systemic inflammation and oxidative stress.
Recent clinical trials have highlighted that certain formulations of IV iron—specifically ferric carboxymaltose (FCM)—carry a significantly higher risk of inducing hypophosphataemia (a severe drop in blood phosphate levels) by triggering a renal phosphate-wasting hormone called FGF23.
Phosphate is critical for cellular energy. When it drops dangerously low, it causes profound muscle weakness, bone pain, and extreme fatigue—ironically mimicking the exact symptoms the iron infusion was meant to cure. Regulatory bodies now warn against this risk, making proactive formulation selection and post-infusion mineral monitoring essential.
The Goodsky Approach: We Test, We Don’t Guess
Trauma therapy asks an incredible amount of energy from the brain and body. If you are entering therapy with a depleted biological floor, or a nervous system stuck in an inflammatory lockdown, the psychological process will feel overwhelming and unsustainable.
This is why, before our guests even arrive at our Sunshine Coast retreat, our clinical team (including our Behavioural Naturopath) initiates comprehensive functional pathology testing. We look beyond standard bloods to evaluate:
- Complete iron studies (including Ferritin and Transferrin saturation) alongside inflammatory markers (CRP).
- Comprehensive NutriSTAT profiles assessing B12, Folate, and Vitamin D.
- Metabolic markers and continuous glucose monitoring (CGM).
- Advanced microbiome mapping (to assess gut-driven inflammation).
If we find anaemia of inflammation, we don’t just blindly force iron into the system. We work to lower the inflammatory alarm bells, regulate the nervous system, and heal the gut so your body feels safe enough to unlock the doors and utilise the fuel it already has. When the body’s energy systems come back online, the heavy cloud of physical “depression” often begins to lift naturally.
Secure Your Biological Foundation
If you feel like you are doing all the right psychological work but your body is still holding you back, it is time for an integrative approach. Our residential programs combine deep somatic trauma therapy with precision metabolic support.
Evidence Base & Further Reading
- Nemeth, E., et al. (2004). IL-6 mediates hypoferremia of inflammation by inducing the synthesis of the iron regulatory hormone hepcidin. Journal of Clinical Investigation.
- Ganz, T. (2018). Iron and infection. International Journal of Hematology.
- Shah, A. A., et al. (2021). Risk of Infection Associated With Administration of Intravenous Iron: A Systematic Review and Meta-analysis. JAMA Network Open.
- Macdougall, I. C., et al. (2019). Intravenous Iron in Patients Undergoing Maintenance Hemodialysis (PIVOTAL Trial). New England Journal of Medicine.
- Wolf, M., et al. (2020). Effects of Iron Isomaltoside vs Ferric Carboxymaltose on Hypophosphatemia in Iron-Deficiency Anemia: Two Randomized Clinical Trials. JAMA.
- Mentzer, P. T., et al. (2023). HEART-FID Trial: Ferric Carboxymaltose in Heart Failure with Iron Deficiency. New England Journal of Medicine.
- Kidney Disease: Improving Global Outcomes (KDIGO) Anemia Work Group. (2026 update). Clinical Practice Guideline for the Management of Anemia in Chronic Kidney Disease.
The content provided in this blog post is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician, psychologist, or other qualified health provider with any questions you may have regarding a medical condition or mental health concern.
