Vitamin B12 Deficiency Anemia: Symptoms and Risks
What Is B12 Deficiency Anemia?
This type of anemia means that your body doesn't have enough healthy red blood cells because you're low in vitamin B12. These cells transport oxygen throughout your body. You need iron and vitamins -- including B12 -- to make red blood cells.
When you don't have enough red blood cells, your body doesn’t get the oxygen it needs to work like it should. Anemia may make you feel tired, weak, and short of breath.
What Causes Vitamin B12 Deficiency Anemia?
You can have vitamin B12 deficiency anemia if you don't get enough vitamin B12 in your diet from foods like milk, eggs, and meat, or if your body can't absorb B12 because of a health problem. Your intestines absorb B12 from food. Here some of the most common reasons for vitamin B12 deficiency:
Pernicious Anemia
This is the most common cause of vitamin B12 deficiency worldwide and mainly affects people of Northern European ancestry. "Pernicious" means "harmful" or "destructive." This type of B12 deficiency anemia can affect many body systems and cause problems in your gut, heart, and muscles. You can get pernicious anemia if:
- You have an autoimmune disease that makes your immune system attack the cells in your stomach that produce intrinsic factor, a protein that helps your body absorb B12.
- You have atrophic gastritis, an inflammation of the stomach lining. This decreases production of intrinsic factor and secretion of hydrochloric acid in the stomach, two things that affect your body's absorption of B12. (Hydrochloric acid separates B12 from the protein it's attached to in food; the freed B12 combines with intrinsic factor so that the body can absorb the vitamin).
- You have a family history of the illness (rare).
Restricted diets
Vitamin B12 is only found in animal products like meat, eggs, and milk. So if you're on a vegan or vegetarian diet where you're not eating foods from animals, you're at risk for B12 deficiency.
Certain health conditions
If you have a stomach or small intestine condition such as celiac disease or Crohn's disease, you may not be able to absorb enough vitamin B12 from food.