Iron: Why Normal Isn’t Good Enough

Written by Grace Petersen, Associate Registered Nutritionist

Iron is having its time in the spotlight right now - and for good reason.

Too many of us have been told our tiredness and anxiety are “just stress,” or reassured that our blood tests are “all normal, so everything’s fine.”

But often, we’re not fine at all.

I know this first hand.

When I was 15, I was training hard for rowing - early mornings, long afternoons, all while managing heavy periods. I was constantly tired, struggling with mood, and could barely keep up with the demands of school and sport.

But my symptoms were dismissed as “normal” for a busy teenage girl.

At 17, I finally pushed for another test. The results were shocking: my iron was just 2 µmol/L and my ferritin was 8 µg/L. I was given an iron infusion, which helped - temporarily. But within three months, my levels had dropped again.

That experience sparked questions that changed the course of my life:

• Why was I losing my iron stores so quickly?

• Why was the only solution to keep topping me up?

• What was the root cause?

Those questions led me into the world of nutrition, and I discovered something vital: iron deficiency is rarely just about “not getting enough.”

It’s about whether your body can absorb and use it - and what’s draining it in the first place.

What is Iron - and Why Does It Matter?

Iron is a mineral, a micronutrient your body cannot make on its own. It’s essential for:

• Haemoglobin: carrying oxygen in your red blood cells

• Myoglobin: storing oxygen in your muscles

• Brain health: making neurotransmitters like serotonin and dopamine

• Immune function: helping immune cells fight infection

• Thyroid and hormones: supporting ovulation and energy regulation

Think of iron as your body’s oxygen delivery driver. Without enough of it, oxygen doesn’t reach your cells efficiently - and energy production grinds to a halt. This is why low iron isn’t just about feeling tired. It can look like:

• Brain fog, poor memory, and difficulty concentrating

• Anxiety, low mood, and loss of motivation

• Frequent infections

• Fertility struggles and irregular cycles

• Stunted growth or delayed learning in children

Deficiency vs. “Normal”

Here in New Zealand, you’re only officially labelled “deficient” if your results fall outside these reference ranges:

• Iron: 10–30 µmol/L

• Transferrin: 2.0–3.6 g/L

• Iron saturation: 20–50%

• Ferritin: 20–200 µg/L

Ferritin (iron storage) is the most sensitive marker - but it can look falsely high if you have inflammation, masking an underlying deficiency.

As you can see these ranges are broad. Designed to detect disease, not to assess whether you’re actually thriving.

That’s why you can sit with an iron of 12 µmol/L and ferritin of 30 µg/L, be told levels are “normal,” yet still struggle with fatigue, heavy periods, and low mood each day.

The Optimal Lens

In clinic, we aim for optimal - not just “acceptable” - levels:

• Iron: >20 µmol/L

• Transferrin: 2.5–3.0 g/L

• Iron saturation: 25–35%

• Ferritin: 100+ µg/L

It’s often not until ferritin climbs over 100 µg/L that people feel the real shift - more energy, emotional stability, better recovery, and stronger resilience.

The Ripple Effects of Low Iron

When iron is low, the consequences extend far beyond tiredness:

• Energy & stamina: fatigue, breathlessness, poor recovery

• Brain & mood: anxiety, low motivation, difficulty concentrating

• Immunity: reduced ability to fight infections

• Hormones & fertility: heavy periods, thyroid issues, irregular ovulation, fertility struggles

• Growth & development: slowed growth, learning challenges in children and teens

Practical Tips: How to Support Healthy Iron Levels

Here’s what you need to know: our body can’t make iron - it must come from food or supplementation.

1. Prioritise Iron-Rich Foods

• Haem iron (best absorbed): red meat, lamb, venison, chicken liver

• Non-haem iron (2-20% absorption): lentils, chickpeas, beans, spinach, pumpkin seeds, quinoa

2. Support Absorption

• Pair iron sources with vitamin C (like capsicum, berries, citrus).

• Ensure you’re getting enough copper and B vitamins, which are critical cofactors.

• Avoid drinking tea or coffee with meals - they can block iron absorption.

3. Identify What’s Blocking You

• Heavy menstrual bleeding, gut inflammation, coeliac disease, or reliance on processed foods can all deplete iron or interfere with absorption.

• Work with a practitioner to uncover and address these root causes - not just patch them with repeat infusions.

4. Supplement Wisely

Not all iron supplements are created equal. Some forms such as ferrous fumarate and ferrous sulfate are poorly absorbed and can cause gut upset. Professional guidance ensures you get the right form, at the right dose, for your needs.

Why All This Matters

Iron deficiency doesn’t just drain your energy - it quietly disrupts your mood, hormones, immunity, and long-term health.

You can be sitting comfortably in the “normal” lab range and still be running on empty.

If you’ve been told “everything is fine” but you know something isn’t right - trust that. Ask for your iron studies, interpret them through the lens of optimal, and seek support from a Nutritionist in finding the root cause of deficiency.