Causes

Vitamin deficiency anemia develops when your body has a shortage of the vitamins needed to produce enough healthy red blood cells. Red blood cells carry oxygen from your lungs throughout your body.

If your diet is lacking in certain vitamins, vitamin deficiency anemia can develop. Or vitamin deficiency anemia may develop because your body can't properly absorb the nutrients from the foods you eat.

Causes of vitamin deficiency anemias include:

Folate deficiency anemia

Folate, also known as vitamin B-9, is a nutrient found mainly in fruits and leafy green vegetables. A diet consistently lacking in these foods can lead to a deficiency.

Deficiency can also result if your body is unable to absorb folate from food. Most nutrients from food are absorbed in your small intestine. You might have difficulty absorbing folate or folic acid, the synthetic form of folate that's added to foods and supplements, if:

• You have a disease of the small intestine, such as celiac disease
• You've had a large part of the small intestine surgically removed or bypassed
• You drink excessive amounts of alcohol
• You take certain prescription drugs, such as some anti-seizure medications

Pregnant women and women who are breast-feeding have an increased demand for folate, as do people undergoing dialysis for kidney disease. Failure to meet this increased demand can result in a deficiency.

Vitamin B-12 deficiency anemia

Vitamin B-12 deficiency can result from a diet lacking in vitamin B-12, which is found mainly in meat, eggs and milk.

However, the most common cause of vitamin B-12 deficiency anemia is a lack of a substance called intrinsic factor, which can be caused when your immune system mistakenly attacks the stomach cells that produce this substance. This type of anemia is called pernicious anemia.

Intrinsic factor is a protein secreted by the stomach that joins vitamin B-12 in the stomach and moves it through the small intestine to be absorbed by your bloodstream. Without intrinsic factor, vitamin B-12 can't be absorbed and leaves your body as waste.

People with endocrine-related autoimmune disorders, such as diabetes or thyroid disease, may have an increased risk of developing pernicious anemia.

Vitamin B-12 deficiency anemia can also occur if your small intestine can't absorb vitamin B-12 for reasons other than a lack of intrinsic factor. This may happen if:

• You've had surgery to your stomach or small intestine, such as gastric bypass surgery
• You have abnormal bacterial growth in your small intestine
• You have an intestinal disease, such as Crohn's disease or celiac disease, that interferes with absorption of the vitamin
• You've ingested a tapeworm from eating contaminated fish. The tapeworm saps nutrients from your body.

Vitamin C deficiency anemia

Vitamin C deficiency can develop if you don't get enough vitamin C from the foods you eat. Vitamin C deficiency is also possible if something impairs your ability to absorb vitamin C from food. For instance, smoking impairs your body's ability to absorb vitamin C.

Certain chronic illnesses, such as cancer or chronic kidney disease, also increase your risk of vitamin C deficiency anemia by affecting the absorption of vitamin C.