Pernicious anemia is a type of vitamin B12 anemia. The body needs vitamin B12 to make red blood cells. You get this vitamin from eating foods such as meat, poultry, shellfish, eggs, and dairy products.
A special protein, called intrinsic factor, helps your intestines absorb vitamin B12. This protein is released by cells in the stomach. When the stomach does not make enough intrinsic factor, the intestine cannot properly absorb vitamin B12.
Common causes of pernicious anemia include:
Weakened stomach lining (atrophic gastritis)
An autoimmune condition in which the body's immune system attacks intrinsic factor protein or the cells that make it.
Very rarely, pernicious anemia is passed down through families. This is called congenital pernicious anemia. Babies with this type of anemia do not make enough intrinsic factor or cannot properly absorb vitamin B12 in the small intestine.
In adults, symptoms of pernicious anemia are usually not seen until after age 30. The average age of diagnosis is age 60.
You are more likely to get this disease if you:
Scandinavian or Northern European
Have a family history of the condition
Certain diseases can also raise your risk. They include:
Todd Gersten, MD, Hematology/Oncology, Palm Beach Cancer Institute, West Palm Beach, FL. Review provided by VeriMed Healthcare Network. Also reviewed by Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington; David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.