Ferritin: what your iron stores say about fatigue and hair loss

What ferritin tells you about your iron stores

Ferritin is the protein in which your body stores iron, mainly in the liver, the spleen and the bone marrow. The amount of ferritin in your blood tracks the size of those stores. That makes ferritin the most widely used marker for detecting an iron deficiency.

An important detail: the stores run out before red blood cell production gets into trouble. So you can already have depleted iron stores while your blood count still looks normal.

Complaints that can fit low iron stores

The best-known complaint is fatigue: a tiredness that does not lift with sleep, often together with becoming short of breath more quickly during exertion, headaches, dizziness on standing up and the feeling of thinking less sharply. Athletes often notice it first in their recovery and in performance that declines without explanation.

There are also complaints that are less quickly linked to iron:

• increased hair loss
• brittle nails
• restless legs in the evening and at night
• hands and feet that feel cold quickly

Here too, none of these complaints proves anything on its own. They all occur in people with perfectly adequate iron stores as well.

Who is more at risk of low iron stores?

Blood loss is the main cause. Women with heavy or prolonged menstruation lose iron every month and therefore find it structurally harder to build up stores. Pregnancy, the period after giving birth and donating blood regularly also draw on the stores. Hidden blood loss from the gastrointestinal tract is another possible cause, and that one in particular calls for assessment by a doctor.

On the supply side, diet and absorption play a role. Iron from meat and fish is absorbed better than iron from plant sources, which makes it harder for vegetarians and vegans to keep their stores up.

Endurance athletes form a separate group: they lose iron through sweat and microscopic blood loss, while their requirement is in fact higher. In addition, bowel conditions such as coeliac disease and Crohn's disease, and long-term use of acid-reducing medication, can reduce absorption.

Ferritin or haemoglobin: what is the difference?

Haemoglobin (Hb) measures how much oxygen-carrying protein is present in your red blood cells. Ferritin measures the reserve your body draws on to make that haemoglobin. So the two say different things.

Anyone who only has their Hb checked can therefore receive a reassuring result while the stores are already nearly empty. That explains why complaints can persist despite a normal blood count.

Note: inflammation can raise ferritin

Ferritin is not only a measure of stores. It is also what is known as an acute-phase protein: with inflammation, infection, liver conditions or excessive alcohol use the value rises, independently of the actual iron stores. As a result, an iron deficiency can be masked.

For that reason ferritin is in practice often assessed together with an inflammation marker such as CRP, and supplemented where needed with iron, transferrin and transferrin saturation. The laboratory states the reference values that apply there alongside your result; those are leading.

Ferritin on its own or the full iron panel?

If you simply want to know how your stores are doing, ferritin as an individual test is enough. If the question has been playing for longer, if you use iron supplements, or if you want to distinguish a deficiency from an excess more reliably, the Iron panel gives the complete picture: ferritin, iron, transferrin, iron-binding capacity and transferrin saturation in a single blood draw.

At Bloodworks you have both drawn at one of the 1000+ collection points in the Netherlands, without a referral, with assessment by a doctor and a personal PDF report.