Why Do We Become Iron Deficient? (The "Leaky Tank" Problem)

Think of your body’s iron like a water tank. You are constantly "using" iron to make blood and repair cells. To keep the tank full, you need to put iron in (through food) and make sure there aren't any holes in the tank (blood loss).Most people become deficient for one of three reasons:

1. The "Iron Leaks" (Blood Loss)

This is the most common cause in Australia. If you lose blood, you lose the iron inside it:

  • Heavy Menstrual Bleeding: This is the #1 cause for women of childbearing age.

  • Internal Leaks: Small "slow-drip" bleeds in the stomach or bowel (often caused by ulcers, polyps, or long-term use of anti-inflammatory meds like Ibuprofen).

2. The "Intake Gap" (Dietary)

If you aren't eating enough iron-rich foods, your body eventually runs out.

  • Vegetarian/Vegan Diets: Plant-based iron (non-haeme) is harder for the body to absorb than iron from meat (haeme).

  • Restrictive Eating: Common in athletes or those with low access to varied nutrition.

3. The "Absorption Wall" (Gut Issues)

Sometimes you eat enough iron, but your gut can't pull it into your bloodstream.

  • Coeliac Disease: Damages the lining of the gut where iron is absorbed.

  • Weight Loss Surgery: Bypassing parts of the stomach or small intestine can significantly reduce iron uptake.

  • The "Coffee/Tea Block": Tannins in tea and coffee can block iron absorption by up to 60–90% if consumed with a meal (BloodSafe, 2026).

The Spectrum: Deficiency vs. Anaemia

Iron deficiency is a journey, not a single event. Doctors categorize it into stages:

Stage 1 & 2: Iron Deficiency (Without Anaemia)

Your "warehouse" (ferritin) is low or empty, but you still have enough iron "in transit" to make red blood cells.

The Feeling: You might feel "flat," experience restless legs, or notice your hair thinning, but a standard "Full Blood Picture" might still look normal.

Stage 3: Iron Deficiency Anaemia (IDA)

Your warehouse is empty, and your body can no longer build enough red blood cells.

The Feeling: Significant breathlessness, heart palpitations, "pica" (craving ice or dirt), and extreme fatigue.

Decoding the Labs: Ferritin and Transferrin

When reviewing your blood results, your GP looks at three primary numbers:

  • Ferritin”: Your "Warehouse" (Storage)

    Guidelines now suggest treating symptoms if ferritin is <30–50 ng/mL, even if the lab range says it's "normal."

  • Transferrin Saturation: Your "Delivery Trucks

    If this is <20%, it means your cells are starving for iron, even if your storage looks okay.

  • Haemoglobin (Hb): The "Finished Product

    If this is low, you have officially reached the stage of Anaemia.

Treatment: Refilling the Tank

1. Oral Replacement (The "Slow and Steady" Path)

  • The Alternate Day Approach: 2026 clinical updates from BloodSafe Australia confirm that taking iron every second day (e.g., Mon/Wed/Fri) reduces side effects like constipation and actually helps the body absorb more iron by keeping a hormone called Hepcidin low.

  • The Vitamin C Rule: Always take iron with Vitamin C and away from tea, coffee, or calcium (dairy).

2. Iron Infusion (The "Express" Path)

If oral iron fails or your levels are critically low, a doctor may suggest an intravenous (IV) infusion (e.g., Ferinject).

  • Pros: Refills your "warehouse" in 15–30 minutes; energy levels usually bounce back in 7–14 days.

  • Cons: Small risk of a permanent "iron stain" at the injection site if the needle dislodges, and a risk of a severe allergic reaction called anaphylaxis, even if you’ve safely had iron infusions before.

Your GP will recommend which type of iron replacement may be best for you.

Australian Resources & Support

Key References