Ferritin levels UK: what's normal, what's low, and what to do.

Ferritin is the protein that stores iron in your body. It is not the same as serum iron, which measures iron currently circulating in your blood, but it is a much better indicator of your iron reserves. When ferritin is low, your body is running short of stored iron, even if your haemoglobin and serum iron still look normal.

UK reference ranges for ferritin.

Reference ranges for ferritin vary between UK laboratories, but the following are typical:

Typical UK ranges by group

Group	Typical range	Notes
Women, not pregnant	13 to 150 µg/L	A wide range. Symptoms often appear below 30 µg/L.
Men	30 to 400 µg/L	Higher stores are typical and low ferritin is less common.
Pregnant women	Varies	A lower threshold is often applied. Iron requirements increase significantly in pregnancy.

What low ferritin feels like.

Low ferritin can cause symptoms even before haemoglobin drops and anaemia develops. This is sometimes called iron deficiency without anaemia, and it is underdiagnosed. Common symptoms include:

• Persistent fatigue, even after adequate sleep
• Hair thinning or increased shedding
• Difficulty concentrating, often described as brain fog
• Restless legs, particularly at night
• Breathlessness on exertion
• Cold hands and feet
• Brittle nails

What causes low ferritin?

The most common causes in UK patients are:

• Not enough iron in the diet. Iron from plants is less easily absorbed than iron from meat, so this is more common in people eating little or no meat.
• Menstrual blood loss. Heavy periods are the most common cause of low ferritin in women of reproductive age.
• Malabsorption. Conditions such as coeliac disease, Crohn's disease and atrophic gastritis impair iron absorption.
• Increased demand. Pregnancy, intense endurance exercise and growth spurts in adolescents all raise iron requirements.
• Chronic blood loss. Gastrointestinal bleeding, from ulcers, polyps or other causes, can deplete iron stores gradually.

What counts as a good ferritin level?

The NHS reference range sets the floor, not the target. Many haematologists consider ferritin below 30 µg/L to be functionally low in patients with symptoms, and some recommend aiming for 50 to 100 µg/L for optimal wellbeing. The right target depends on your individual circumstances, your symptoms and any underlying conditions.

Can ferritin be too high?

Yes. Elevated ferritin, above 200 µg/L in women or above 300 µg/L in men, can indicate iron overload, chronic inflammation, liver disease or other conditions. Ferritin is an acute phase reactant: it rises during infection or inflammation even when iron stores are normal. A high ferritin result always warrants investigation.

What to ask your GP.

• What is my ferritin level, and how does it compare to my previous tests?
• Should I have a full iron panel as well: serum iron, TIBC and transferrin saturation?
• Is my ferritin low enough to explain my symptoms?
• If supplementation is appropriate, what dose and form do you recommend?
• Should we investigate the cause, particularly if it keeps recurring?