Pernicious anemia is more common in people of Northern European and African descent than in other ethnic groups.
Older people also are at higher risk for the condition. This is mainly due to a lack of stomach acid and intrinsic factor, which prevents the small intestine from absorbing vitamin B12. As people grow older, they tend to make less stomach acid.
Pernicious anemia also can occur in younger people and other populations. You're at higher risk for pernicious anemia if you:
- Have a family history of the condition.
- Have had part or all of your stomach surgically removed. The stomach makes intrinsic factor. This protein helps your body absorb vitamin B12.
- Have an autoimmune disorder that involves the endocrine glands, such as Addison's disease, type 1 diabetes, Graves' disease, or vitiligo. Research suggests a link may exist between these autoimmune disorders and pernicious anemia that's caused by an autoimmune response.
- Have had part or all of your small intestine surgically removed. The small intestine is where vitamin B12 is absorbed.
- Have certain intestinal diseases or other disorders that may prevent your body from properly absorbing vitamin B12. Examples include Crohn's disease, intestinal infections, and HIV.
- Take medicines that prevent your body from properly absorbing vitamin B12. Examples of such medicines include antibiotics and certain seizure medicines.
- Are a strict vegetarian who doesn't eat any animal or dairy products and doesn't take a vitamin B12 supplement, or if you eat poorly overall.