Hepcidin

Hepcidin is a hormone that controls how your body uses iron, an important mineral your body needs. Iron is an essential building block of a protein called hemoglobin.

Hemoglobin is the most important component of your red blood cells. It binds to oxygen, enabling your red blood cells to transport oxygen to tissues and organs throughout your body. Iron is also a building block of myoglobin, a protein that provides oxygen to your muscles and heart.

Healthcare providers may call hepcidin the “master iron regulator” because it controls how much iron is available for your cells to perform essential processes. Too little iron can lead to conditions like iron-deficiency anemia, where your body doesn’t make enough red blood cells. Too much iron can be toxic (poisonous) and even life-threatening.

What does hepcidin do?

Hepcidin regulates how your body absorbs iron. This complex process starts when cells in your small intestine (enterocytes) absorb iron from the food you eat. Cells in your small intestine contain ferritin. This is a protein that stores iron in your small intestine.

When your body needs iron, another protein called ferroportin moves iron from your small intestine into your bloodstream. Ferroportin is the only known iron exporter protein. It provides the only route iron can take to get from your small intestine to your bloodstream.

Hepcidin acts like a worker managing how vehicles pass through a construction zone. It blocks ferroportin so it can’t move iron into your bloodstream.

Your liver makes hepcidin. When your iron levels drop, your liver makes less of it. This gives ferroportin the go-ahead to move iron into your bloodstream. When your liver makes more hepcidin, the hormone blocks ferroportin so it can’t move stored iron.

Hepcidin also controls when recycled iron is released into your bloodstream. This process starts when your red blood cells begin to die. When this happens, immune cells destroy the dying cells and capture the iron in the cells’ hemoglobin. Hepcidin controls whether the cells store the captured iron or release it into your bloodstream.

What conditions are associated with abnormal hepcidin levels?

Certain conditions may affect how hepcidin your liver makes.

High levels

Conditions that can lead to high levels are:

• Non-iron deficiency anemia: This is a genetic condition where you have too much hepcidin.
• Anemia of chronic disease: This condition causes chronic inflammation. Long-term inflammation can affect your body’s ability to use iron to make red blood cells.

Low levels

Conditions linked to low levels include:

• Iron-deficiency anemia: This is the most common type of anemia linked to low levels.
• Hereditary hemochromatosis: This condition happens when you inherit genetic changes (variations) that keep your liver from releasing hepcidin.
• Iron-loading anemias: Conditions like thalassemia and sideroblastic anemia affect how your bone marrow makes red blood cells. Your hepcidin levels drop when your body needs more hemoglobin and iron to make red blood cells. 
• Hepatitis C: This virus stops your liver from making the hormone.

Other issues can affect hepcidin levels, like:

• Infections: Harmful germs like bacteria use iron to thrive. When you have an infection, your liver makes more hepcidin so your body doesn’t release as much iron.
• Insulin: This hormone affects how much hepcidin your liver makes. Low insulin levels can lead to iron overload.
• Iron levels: Low iron levels signal your body to make less hepcidin, while high iron levels signal your body to produce more of it.
• Low oxygen levels (hypoxia): Your body stops making hepcidin when you have hypoxia.

Signs/symptoms something isn’t working right

High and low hepcidin levels lead to various types of anemia (low red blood cell levels). Anemia causes symptoms like:

• Fast heart rate
• Fatigue
• Pallor
• Shortness of breath