People who have pernicious anemia can’t absorb enough vitamin B12 from food. This is because they lack intrinsic (in-TRIN-sik) factor, a protein made in the stomach. A lack of this protein leads to vitamin B12 deficiency.
What can cause a lack of intrinsic factor?
The inability to make intrinsic factor may be caused by several things, such as:
- Chronic gastritis.
- Surgery to remove all or part of the stomach (gastrectomy)
- An autoimmune condition, where the body attacks its own tissues.
What autoimmune disease causes lack of intrinsic factor?
Pernicious anemia is a rare condition characterized by vitamin B12 deficiency anemia due to lack of intrinsic factor, often caused by autoimmune gastritis.
Does intrinsic factor make B12?
Vitamin B12 binds to the protein in the foods we eat. In the stomach, hydrochloric acid and enzymes unbind vitamin B12 into its free form. From there, vitamin B12 combines with a protein called intrinsic factor so that it can be absorbed further down in the small intestine.
What is meant by intrinsic factors?
Intrinsic factors include the genetic, physiological, and pathological characteristics of an individual; in other words, these are traits that are “intrinsic” to a person rather than being determined by that person’s environment.
Why is pernicious anemia considered an autoimmune disease?
Pernicious anemia is an autoimmune disease caused by vitamin B12 deficiency due to atrophic gastritis or loss of parietal cells or lack of intrinsic factor.
What is intrinsic factor required for?
Intrinsic factor (IF), also known as gastric intrinsic factor (GIF), is a glycoprotein produced by the parietal cells (in humans) or chief cells (in rodents) of the stomach. It is necessary for the absorption of vitamin B12 later on in the distal ileum of the small intestine.
What medications should not be taken with B12?
Certain medications can decrease the absorption of vitamin B12, including: colchicine, metformin, extended-release potassium products, antibiotics (such as gentamicin, neomycin, tobramycin), anti-seizure medications (such as phenobarbital, phenytoin, primidone), medications to treat heartburn (such as H2 blockers …
What are the root causes of pernicious anemia?
Too many of the wrong kind of bacteria in the small intestine.
How serious is pernicious anaemia?
Pernicious anemia can cause permanent damage to nerves and other organs if it goes on for a long time without being treated. It also raises the risk for developing stomach cancer. Pernicious anemia is diagnosed using family history and medical history, a physical exam, and diagnostic tests and procedures.
What conditions cause pernicious anemia?
Pernicious anemia is caused by a lack of intrinsic factor or other causes, such as infections, surgery, medicines, or diet. Intrinsic factor is a protein made in the stomach. It helps your body absorb vitamin B12. In some people, an autoimmune response causes a lack of intrinsic factor.
