Vitamin deficiency anemia can happen from not eating enough foods that have vitamin B-12 and folate, or from the body having trouble taking in and using these vitamins.
Vitamin B-12 deficiency
The following can cause low levels of vitamin B-12:
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Pernicious anemia. With this condition, the body's immune system attacks cells in the stomach that make a substance called intrinsic factor. Without this substance, the intestines can't take in B-12.
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Gastric surgeries. Having surgery that removes parts of the stomach or intestines can lessen the amount of intrinsic factor the body makes and lessen the area the body has to take in vitamin B-12.
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Intestinal conditions. Crohn's disease and celiac disease can keep the body from taking in vitamin B-12. So can tapeworms. Eating tainted fish can cause tapeworms.
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Diet. Vitamin B-12 is mainly in meat, eggs and milk. So people who don't eat these foods may need to take B-12 supplements. But diet isn't often the cause of vitamin B-12 deficiency.
Folate deficiency
Also known as vitamin B-9, folate is mainly in dark green leafy vegetables and liver. A folate deficiency can happen when people don't eat foods that have folate, or their bodies can't take in folate from food.
The following can cause low levels of folate:
- Conditions of the intestines, such as celiac disease.
- Surgical removal or bypass of a large part of the intestines.
- Drinking a lot of alcohol.
- A diet low in folate.
- Prescription medicines, such as some antiseizure medicines.
People who are pregnant or breastfeeding have a greater need for folate. So do people who get dialysis for kidney disease.
Not enough folate can cause birth issues during pregnancy. But folate deficiency is less common in countries where food makers add folate to food products such as breads, cereals and pasta.