Folate-deficiency anemia is a decrease in red blood cells (anemia) due to a lack of folate.

Folate, also called folic acid, is necessary for red blood cell formation and growth. You can get folate by eating green leafy vegetables and liver. Some medications, such as phenytoin (Dilantin), interfere with the absorption of this vitamin. Because folate is not stored in the body in large amounts, a continual dietary supply of this vitamin is needed to maintain normal levels.

In folate-deficiency anemia, the red cells are abnormally large. These large cells are called megalocytes, or megaloblasts in the bone marrow. That is why this anemia can also be called megaloblastic anemia.

Causes of this anemia are:

• Certain medications
• Diseases such as celiac disease (sprue), which reduce absorption of folic acid from the diet
• Poor dietary intake of folic acid

In the third trimester of pregnancy, a woman may have a deficiency due to an increased need for folic acid. Hemolytic anemia can also cause a deficiency due to increased red blood cell destruction.

Risk factors include:

• Alcoholism (which interferes with the absorption of folate)
• Eating overcooked food
• History of malabsorption diseases
• Poor diet (often seen in the poor, the elderly, and people who do not eat fresh fruits or vegetables)
• Pregnancy

The disease occurs in about 4 out of 100,000 people.

• Fatigue
• Headache
• Pallor
• Sore mouth and tongue

• Bone marrow examination (rarely necessary)
• Complete blood count (CBC)
• Red blood cell folate level

The goal is to identify and treat the cause of the folate deficiency.

Folic acid supplements may be given by mouth (oral) or through a vein (intravenous) on a short-term basis until the anemia has been corrected. In the case of poor absorption by the intestine -- replacement therapy may be lifelong.

Dietary treatment consists of increasing the intake of green, leafy vegetables and citrus fruits.

Anemia usually responds well to treatment within 2 months.

Symptoms of anemia can cause discomfort. In pregnant women, folate deficiency has been associated with neural tube or spinal defects (such as spina bifida) in the infant.

Call for an appointment with your health care provider if you have symptoms of folate deficiency anemia.

Good dietary intake of folate in high-risk individuals, and folic acid supplementation during pregnancy may help prevent this anemia.

Antony AC. Megoblastic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 170.