What is Vitamin B12?
Vitamin B-12, or cobalamin, is a nutrient you need for good health. It's one of eight B vitamins that help the body convert the food you eat into glucose, which gives you energy. Vitamin B-12 has a number of additional functions. Vitamin B12 is a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells. Vitamin B12 also helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak.
Two steps are required for the body to absorb vitamin B12 from food. First, hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body. Some people have pernicious anemia, a condition where they cannot make intrinsic factor. As a result, they have trouble absorbing vitamin B12 from all foods and dietary supplements.
Vitamin B12 Deficiency
Most people in the U.S. get enough of this nutrient. However, If you’re not sure, you can ask your doctor if you should get a blood test to check your vitamin B12 level.
With age, it can become harder to absorb this vitamin. It can also happen if you have had weight loss surgery or another operation that removed part of your stomach, if you drink heavily, or if you’ve taken acid-reducing medications for a long time.
You may also be more likely to develop vitamin B12 deficiency if you have:
- Atrophic gastritis, in which your stomach lining has thinned
- Pernicious anemia, which makes it hard for your body to absorb vitamin B12
- Conditions that affect your small intestine, such as Crohn's disease, celiac disease, bacterial growth, or a parasite
- Immune system disorders, such as Graves' disease or lupus