Definition: Intrinsic factor is a protein that helps your intestines absorb vitamin B12. It is made by cells in the stomach lining.
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.
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.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of any other sites. Content provided by A.D.A.M and is prepared for the United States of America. Recommended treatments may not be applicable, available, or permissible in Canada or other jurisdictions. A.D.A.M. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC’s accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch