What are normal iron levels?

Iron is important for heme production, which enables your red blood cells to carry oxygen to all the cells in your body. It is essential for life. But what are normal iron levels? The answer depends on your age and sex, so let's take a closer look.

A healthcare provider might want to test iron levels. Testing for blood iron levels can be done in many providers’ offices and clinics. Your provider may use the following tests to check iron levels and certain types of blood counts in your body:

• Serum iron: This test measures how much iron is in your blood. The iron circulating in the blood (not stored in other parts of the body) can attach itself to a protein called transferrin. Normal values for serum iron, like most of these measurements, is a range, not a fixed number.
• Hemoglobin: This is a protein in your blood that carries oxygen to the tissues in your body. A lower than normal hemoglobin level means you have a low red blood cell count, which is called anemia. An iron deficiency is the most common cause of anemia.
• Hematocrit: This is the percentage of blood volume that red blood cells make up. A lower than normal hematocrit level could mean you have anemia.
• Transferrin: This is the main protein that carries iron in the blood. During a blood test, the lab can measure transferrin in one of two ways: directly, reporting a transferrin level, or indirectly, calculated from measurements of other blood components, also referred to as the total iron-binding capacity (TIBC).
• Total iron-binding capacity: An indirect measurement of transferrin, the TIBC is an assessment of your body's ability to transport iron.
• Ferritin: This protein helps store iron in your body. A low level of ferritin usually means lower stores of iron in the body.

The typical normal values for the most common tests to evaluate iron deficiency are listed below. Note that your healthcare provider may have different goal ranges for you. Ask your provider what your iron test results mean.

The normal ranges for the following tests are the same for men, women and children:

• TIBC: 240–450 mcg/dL
• Transferrin: 20%–50%

Average iron levels for children can vary by age, as seen with hemoglobin in the table below. Ask your child’s healthcare provider what their iron test results mean.

There are many conditions and medicines that can affect iron levels. Low serum iron levels can be caused by conditions such as:

• Low dietary intake of iron 
• Blood loss —the most common cause of iron deficiency due to chronic loss from the gastrointestinal tract or from chronic, heavy menstrual flow
• Intestinal conditions that interfere with the absorption of iron — such as surgery to remove part of the stomach or small intestine
• Pregnancy — which increases risk of complications to the fetus and mother during pregnancy
• Infections or diseases

High iron levels can be caused by conditions such as:

• Hemochromatosis — a hereditary condition that causes your body to absorb too much iron from the foods you eat
• Certain blood disorders — such as hemolytic anemia, thalassemia and sickle cell disease
• Hepatitis — inflammation of the liver, or other liver diseases
• Iron poisoning from supplements
• Frequent blood transfusions

Some medicines may also affect your iron level, including:

• Birth control pills, which may reduce the risk of anemia with lighter menstrual periods

Some medicines may increase your risk for anemia, such as:

• Nonsteroidal Anti-inflammatory Drugs (NSAIDS)
• Quinine
• Certain antibiotics
• Methyldopa
• Cancer treatment such as chemotherapy medicines and radiation

Iron is important for your health, and it's necessary to keep it at an appropriate level. If you are concerned your iron levels are too low or too high, consult with your healthcare provider. A simple blood draw can give you the answers you need.

Clinically reviewed and updated by Julie McDaniel, MSN, RN, CRNI September 2023.