Always Tired? It Might Be Your Iron
Iron deficiency is one of the most common nutritional deficiencies in the world, and it's especially common among menstruating women. So it's worth understanding a few key facts - and clearing up a few myths - about low iron and how it's assessed.
Some of the common signs associated with low iron include fatigue, irritability, headaches, restless legs, cramps, and changes in your hair, skin and nails.
Iron is one of the first things I encourage patients to check each year - and not just ferritin. I like to see a full iron studies panel, so we can understand both what your iron stores look like and how your body is moving iron around to the tissues and organs that need it.
What causes low iron?
Low iron usually comes down to one of three things: losing iron, not taking enough in, or not absorbing it well.
Blood loss - the most common cause, particularly through heavy menstruation
Low dietary iron - not getting enough iron-rich foods in the first place
Poor absorption - when your body isn't taking up the iron you're eating
It's also worth knowing that some foods and drinks can interfere with how well you absorb iron. Tannins in tea and coffee are common culprits, and calcium-rich foods (like cheese) eaten alongside iron-rich foods (like meat) can get in the way of optimal absorption. A little timing awareness - keeping that morning coffee away from your iron-rich meal, for instance - can make a real difference.
Testing your iron
To get an accurate picture, it's worth making sure your blood test includes:
FBC (full blood count), including haemoglobin
CRP - a useful marker of general inflammation
Full iron studies, including:
Ferritin - your stored iron. We think of this as the iron “waiting at the depot.”
Transferrin - the “taxi service” that delivers iron around the body. Generally, fewer taxis suggests the body is content with its current stores; more taxis suggests it's hungry for iron.
Transferrin saturation - “how many passengers are in the taxis.” Around 20-30% is often considered ideal.
A transferrin saturation above the reference range can point toward iron overload. The C282Y genotype linked to haemochromatosis is found in around 90% of people with a fasting transferrin saturation at or above 45% - which is why a persistently elevated saturation (generally above 45% in men or 55% in women, alongside raised ferritin) is worth discussing with your GP, who may consider a haemochromatosis gene test. Read more here.
If I had to choose the single most telling marker of iron storage and use for most women, it would be transferrin.
Getting the most accurate result
A few things that help your iron studies reflect your true levels:
Test in a fasted state where possible - ideally no food for 10-12 hours beforehand (water is fine). First thing in the morning is easiest for most people. Eating beforehand can make iron look higher than it really is.
Stop iron-containing supplements 48 hours before your test.
Avoid strenuous or endurance exercise for 24 hours beforehand (gentle movement like walking or yoga is fine).
It's also worth knowing that iron results are naturally altered by the oral contraceptive pill, pregnancy and menopause. In the third trimester, for example, it's common to see a natural dip in ferritin and saturation, and a rise in transferrin.
A note on iron supplements
Here's a myth worth busting: more isn't always better. Research suggests that very high daily doses of iron may not be the most effective way to restore your levels.
One study found that iron doses of 60mg or higher raised hepcidin - a hormone that regulates iron absorption - for up to 24 hours, and were associated with lower absorption the following day. In other words, how and when you take iron can matter just as much as how much - which is why some research suggests alternate-day dosing may be more effective than daily or twice-daily dosing.
Many over-the-counter iron supplements come in high single doses, so if you've been taking iron daily without seeing much change, it's worth reviewing your approach with a practitioner - the strategy often matters more than the strength.
Want to understand your own iron story?
If you'd like a full iron studies panel interpreted properly - not just a ferritin number in isolation - and personalised naturopathic support to match, that's exactly what we do together. Let's get to the bottom of how you're really feeling.
We take a multifactorial approach, drawing on naturopathic, dietary and homeopathic support. Together we look at dietary iron sources, ways to improve iron absorption, whether supplementation is appropriate for you, and how to maintain healthy levels over time.
One of my quiet favourites in this space is Ferrum phosphate (iron phosphate) - available as a tissue salt or homeopathic remedy, and traditionally used to iron support.
This article was written by Olivia McFadyen, founder of Sora Sol and a qualified, accredited Homeopath, Naturopath, Nutritionist and Herbalist. It is intended as general education only and is not a substitute for individualised health advice. Please speak with your GP or a qualified healthcare practitioner before starting any product, supplement or remedy, or making changes to your healthcare.