- Most people absorb vitamin B12 from food such as eggs, diary and meat. Vitamin B12 is essential for your body to create new red blood cells, which carry oxygen around your body. It also has a role in helping your nerves and brain function.
- Pernicious anaemia is an autoimmune condition where your immune system attacks cells in your stomach that make a protein called intrinsic factor. Intrinsic factor is needed for your body to absorb vitamin B12 from the food you eat.
- Without enough vitamin B12, you can feel tired, weak and lethargic. Over time, a lack of vitamin B12 can lead to serious health problems.
- Treatment involves vitamin B12 injections.
What causes pernicious anaemia?
In pernicious anaemia, your body can't make enough healthy red blood cells because it doesn't have enough vitamin B12. This is caused by a lack of intrinsic factor, a protein made in your stomach. Without enough vitamin B12, your red blood cells don't divide normally and can’t carry out their job of moving oxygen around your body.
Other causes of low vitamin B12 include:
- digestive conditions, such as Crohn's disease and coeliac disease
- surgery to remove parts of your bowel
- some medicines that affect the absorption of vitamin B12, such as proton pump inhibitors
- not getting enough B12 from your food, eg, from having a strict vegan diet.