This week's article was inspired by a thoughtful question from one of our Members. She was pleased to find out that she wasn’t iron deficient. But when she received the results of her latest blood tests, she found out she was anaemic.

It prompted an excellent question:

How can I have anaemia if my iron levels are normal?

The short answer is that while iron deficiency is the most common cause of anaemia, it isn't the only one.

Anaemia is a diagnosis, not a cause

Anaemia simply means your blood doesn't contain enough healthy red blood cells (in number or size) or haemoglobin, needed to carry oxygen around the body – a mighty important role. Think of anaemia as the end result rather than the reason. Iron deficiency is one pathway that can lead to anaemia, but so can deficiencies of vitamin B12 and folate, chronic inflammation, kidney disease, certain medications and several other medical conditions. That's why it's important find the driver of the anaemia.

Why vitamin B12 and folate matter

Your bone marrow is constantly producing new red blood cells – two million every second! To build healthy red blood cells, your body needs iron, yes but it also requires adequate vitamin B12 and folate, which are also essential for DNA synthesis and normal cell division. When either nutrient is lacking, the body struggles to produce healthy red blood cells. Instead, the cells become larger than usual (with B12 and folate issues; they become smaller with iron deficiency) and fewer are released into circulation, resulting in a type of anaemia known as megaloblastic anaemia. In other words, even if your iron stores are excellent, a shortage of vitamin B12 or folate can still leave you anaemic.

Who is more likely to have low vitamin B12?

Vitamin B12 is found exclusively in animal-derived foods (although some packaged vegetarian foods are fortified with synthetic B12 and its absorption can be a concern), so people following vegetarian or vegan diets may be at higher risk of deficiency. Because stomach acid helps to release vitamin B12 from food, having robust digestion is also essential. Digestive conditions such as coeliac disease, Crohn's disease and pernicious anaemia (a type of anaemia where your immune system attacks your stomach cells) can also interfere with absorption, as can some commonly prescribed medications, like some that are used to treat reflux. The persistent production of stress hormones may also contribute to poor stomach acid production and therefore the absorption of vitamin B12 (and non-haem iron).

If vitamin B12 deficiency is suspected, I often recommend discussing an active vitamin B12 (holotranscobalamin) blood test with your healthcare practitioner, as it provides a better indication of the vitamin B12 that is available for your cells to use than a total vitamin B12 level alone.

What about folate?

Folate is naturally abundant in leafy green vegetables, legumes, asparagus, avocado and citrus fruits. Although severe folate deficiency is less common today than it once was, it can still occur in people whose vegetable intake is low, whose requirements are increased, or whose absorption is compromised. Because vitamin B12 and folate work closely together, both are often assessed when investigating anaemia.

It’s always the path in

If you've been diagnosed with anaemia, it's important to understand why. Iron studies can tell us whether iron deficiency is involved, yet they don't always tell the whole story. Exploring what else might be driving this is essential to correcting it because the road in is always the road out. The goal isn't simply to correct a blood test result. It's to understand what's preventing your body from producing healthy red blood cells in the first place.

Iron deficiency is the most common driver and needs to be addressed when it's present. Yet, if your iron levels are excellent and anaemia remains, it's worth remembering that your body may be asking for something else.