Serum Ferritin

What is Ferritin?

Ferritin is a protein that stores iron and releases it as needed. Iron is of great importance for the whole body. Red blood cells need iron to carry oxygen. The deficiency of iron in the body or its excess can cause many problems. Ferritin is found in almost all cells of the body, but its highest concentration is in the liver cells.

The amount of serum ferritin is almost equal to its total content in the body. If the body lacks ferritin, iron stores can quickly become depleted. Therefore, ferritin is an informative indicator of the level of iron both in healthy people and in people with uncomplicated forms of iron deficiency anemia. In the acute inflammatory process, a high level of ferritin may be a marker of acute phase-response, as it belongs to the group of acute-phase proteins.

Serum Ferritin

Interpret now "Complete Blood Count (CBC)"
Interpret now "Urinalysis (UA)"

Determining the level of ferritin is an important factor for the differential diagnosis of anemia, tumors, chronic infectious and inflammatory diseases, hemochromatosis. The determination of serum ferritin helps differentiate true iron deficiency anemia (IDA), as it displays the total amount of iron accumulated in the body.

A blood test for ferritin can be performed together with a blood test for iron, a total serum iron-binding capacity (TIBC), and a transferrin test. These lab tests provide additional information on the amount of iron in the body.


During pregnancy, the need for iron increases. By the second trimester, the daily requirement for iron increases by 3 times compared with non-pregnant women, which increases the likelihood of developing iron deficiency (ID) in the absence of proper nutrition or taking iron supplements. It is believed that iron deficiency is the cause of half of the cases of anemia during pregnancy.

Units of Measure

The number of red blood cells can be expressed in international units:

  • nmol/L (nanomole/liter)
  • pmol/L = picomole/liter

Conventional units:

  • ng/mL (nanogram/milliliter)
  • µg/L (microgram/liter)
  • µg/dL (microgram/deciliter)
  • µg/100mL (micrograms/100 milliliters)
  • µg% (micrograms percent)

Conversion factors:

  • µg/L = ng/mL
  • ng/mL = µg/dL = µg/100mL
  • 1 ng/mL = 2.247 pmol/L

Normal Range

The determination of ferritin is the most informative test for the diagnosis of iron deficiency anemia, the prognostic result of which is 95%. When interpreting the test results, it is necessary to take into account gender, age, pregnancy, menstrual cycle, and iron supplements intake.

Normal ferritin values may vary from lab to lab. According to the World Health Organization (WHO), ferritin levels less than 15 ng/mL indicate depleted iron stores and more than 150 ng/mL in women (> 200 ng/mL in men) indicate acute iron overload.

Ferritin Normal Range in Pregnancy

During pregnancy, the mother's iron stores are spent on the needs of a growing baby and placenta. The body needs additional iron to increase the number of red blood cells in the blood, as well as to replace the loss of iron due to bleeding during labor.

According to the World Health Organization (WHO), during pregnancy, anemia is diagnosed when the hemoglobin level is less than 11 g/dL.

If a pregnant woman is not anemic, iron deficiency (ID) is diagnosed with a ferritin level of less than 15 ng/mL. If a pregnant woman has anemia (when all other causes of anemia are excluded), a ferritin level less than 40 ng/mL indicates iron deficiency anemia. [1]

Serum Ferritin Levels in Children

The normal ferritin levels for children are different from those for adults.

Serum Ferritin
Age Reference interval
1 month200-600
2-5 months50-200
6 months – 15 years7-140

Reference intervals may vary in different laboratories.

Low Ferritin

Iron deficiency and anemia are not the same things. Anemia means a lack of hemoglobin in the blood. Symptoms of anemia and iron deficiency are similar. But the body may lack iron without anemia. Doctors often check for anemia and do not always take into account the possibility of iron deficiency without anemia.

Low ferritin is an early stage of iron deficiency in the body. This means that iron is still enough for the production of red blood cells, but the reserves are not completely replenished. As iron levels decrease, transferrin levels increase to increase iron transport. Red blood cells are produced less and less, which leads to iron deficiency anemia.

Iron deficiency can occur even at a reduced level of ferritin, which is not lower than normal (<30 ng/mL). This condition is also called “latent iron deficiency” or “depleted iron stores”, and the corresponding symptoms may appear. However, iron deficiency can occur even at higher serum ferritin concentrations than 30 ng/mL. [2]

In women without inflammation or other disorders, serum ferritin levels lower than or equal to 30 ng/mL are closely associated with telogen hair loss. [3]

Symptoms of Low Ferritin

Ferritin is a marker of iron stores in the body. Iron plays an important role in maintaining the energy level in the body, maintaining the functions of the thyroid gland, as well as in many other important processes. Therefore, symptoms of iron deficiency can manifest in different ways. Low iron levels usually cause one or several symptoms:

  • fatigue, weakness
  • dizziness
  • shortness of breath, chest pain, especially during physical activity
  • headache
  • pale skin
  • hair loss, brittle nails
  • ringing in your ears
  • decreased immunity

Causes of Low Ferritin

The most common causes of low ferritin levels are:

  • heavy menstrual bleeding
  • insufficient amount of iron in the diet (Plant-based diets with little meat)
  • pregnancy
  • malabsorption syndrome (loss of nutrients as a result of malabsorption in the small intestine)
  • chronic internal bleeding (ulcer, polyps)
  • autoimmune diseases (celiac disease)

Low Ferritin Levels in Pregnancy

Pregnancy and breast-feeding deplete iron stores in the body. Additional iron is needed to increase red blood cell volume and replace the loss of iron due to bleeding during labor.

Low maternal serum ferritin levels are associated with iron deficiency in newborns. [4]

In addition to negative effects on the fetus, maternal iron deficiency anemia is associated with an increased risk for cesarean section, perinatal bleeding, preeclampsia, placental abruption, maternal thyroid disease, impaired wound healing, heart failure, and death. [5]

Low Ferritin Levels in Children

An adult needs to eat very poorly in order to develop iron deficiency due to malnutrition. But for children, low levels of iron in the body are the most common nutritional disorder in the world. [6]

Children aged 6 to 24 months with iron deficiency anemia are at risk of cognitive, motor, social-emotional and neurophysiologic development in the short- and long-term outcome. [7]


The goal of treating iron deficiency is to provide enough iron to the body and to normalize hemoglobin concentration in the presence of anemia. You should always consider the underlying cause of the iron deficiency and eliminate it in the first place.

If you have low ferritin levels, your doctor may advise taking iron supplements, as well as eating foods rich in iron.

High Ferritin

Too high levels of ferritin may be due to a number of reasons that do not reflect the actual iron stores in the body:

  • acute or chronic inflammation
  • daily alcohol consumption
  • liver disease
  • renal failure
  • malignant tumors, such as acute leukemia and Hodgkin's disease

The most common reason high ferritin levels is hemochromatosis – a hereditary (genetic) disease in which there is an excessive accumulation of iron in the body (iron overload).

Ferritin can also increase due to excess iron intake (hemodialysis or transfusion), hyperthyroidism, type 2 diabetes, high body mass index (obesity).

High Ferritin Levels in Pregnancy

High levels of hemoglobin, hematocrit, and ferritin are associated with an increased risk of fetal growth restriction, premature birth, and preeclampsia.

High Ferritin Levels in Children

In children under 6 months of age, slightly higher ferritin levels can be seen, then the values gradually drop to the level of an adult.

In children, iron poisoning can occur if too many iron supplements are taken.


Treatment in patients with elevated ferritin levels in the blood depends on the underlying disease that caused this increase.

For example, doctors can treat hemochromatosis by regularly removing blood from your body (phlebotomy), like a normal blood donation. The goal of phlebotomy is to lower the levels of iron in the body.

Comprehensive Metabolic Panel (CMP) Interpretation