MedlinePlus Medical Encyclopedia: Intrinsic factor

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Intrinsic factor

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Definition Information	References

Definition Return to top

Intrinsic factor is a protein produced by cells in the stomach lining. It is needed for the intestines to absorb vitamin B12 efficiently.

Information Return to top

Immune system damage to the stomach lining can cause a lack (deficiency) of intrinsic factor. This can lead to vitamin B12 deficiency and low red blood cell count (anemia), which is called pernicious anemia. Intrinsic factor deficiencies can be caused by other reasons, such as surgical removal of the stomach, inherited conditions, and other diseases.

References Return to top

Antony AC. Megaloblastic anemia. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 170.

Update Date: 11/23/2008

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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