Low Iron? Why Supplements Aren’t Always the Answer

Low iron is incredibly common — and for many people, the first response is to reach for an iron supplement.

But if iron supplements alone were the answer, far fewer people would still be struggling with low iron months (or years) later.

Iron deficiency is rarely just a “low intake” problem

While inadequate dietary intake can play a role, iron status is influenced by several factors, including:

• How much iron you lose

• How well your body absorbs iron

• Whether inflammation or infection is blocking absorption

• Whether iron is being properly utilised once absorbed

This is why iron supplementation works well for some people — and barely moves the needle for others.

Testing first matters

I never recommend iron supplementation without testing. Ferritin is commonly measured, but it doesn’t always tell the full story, particularly when inflammation is present. Ferritin is an acute-phase reactant, meaning it can appear “normal” or elevated even when iron availability is low.

Where possible, additional markers such as transferrin and transferrin saturation help clarify whether iron is truly available to the body.

The four key reasons iron may be low

When addressing iron deficiency, I always consider four areas:

1. Intake
Some people simply aren’t consuming enough iron-rich foods. This is more common in those eating little or no animal protein, as plant-based iron is less bioavailable.

2. Loss
Iron loss is significant in some people, particularly with:

• Heavy or prolonged menstrual bleeding

• Frequent blood donation

3. Absorption
Iron absorption depends on:

• Adequate stomach acid

• A healthy gut lining

• A balanced microbiome

Gut conditions such as coeliac disease or chronic gut inflammation can significantly impair absorption.

4. Inflammation and stress
Inflammation — whether from infection, gut issues, chronic stress or metabolic imbalance — can actively block iron absorption, even when intake is adequate.

When supplements don’t work

If iron levels don’t improve despite supplementation and dietary changes, it’s often a sign that:

• The underlying cause hasn’t been addressed

• Absorption is impaired

• Inflammation is overriding iron uptake

In these cases, increasing the dose is rarely the solution.

Next step: In the next blog, I explain why how you take iron matters just as much as whether you take it — including dosing strategies that can improve absorption and reduce side effects.

Please get in touch if you’d like to discuss this topic further.

Disclaimer: This blog is for information purposes only. By providing, the information contained herein, we are not diagnosing, treating, mitigating, or preventing any type of disease or medical condition. Before beginning any type of natural, integrative or conventional treatment of any sort, we advise you seek the advice of a qualified health professional.