search buttonmobile navigation expand button

The information contained on this page is provided as general health information and is not intended to substitute as medical advice and direction from your physician or health care provider. Please direct any questions related to your health care provider. In an emergency, call 9-1-1 or go to the nearest emergency center.


Intrinsic factor

Definition

Intrinsic factor is a protein that helps your intestines absorb vitamin B12. It is made by cells in the stomach lining.

Information

Intrinsic factor binds to vitamin B12. After attaching, intrinsic factor and B12 travel to the intestines to be absorbed into the bloodstream. Vitamin B12 is needed for red blood cells to form and grow.

Some people do not make enough intrinsic factor or have a condition that destroys it. If your body does not make enough intrinsic factor, you can develop a type of vitamin B12 deficiency called pernicious anemia.

Surgical removal of the stomach and certain other health conditions can also cause you to stop making intrinsic factor.

References

Antony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 39.