Folate deficiency means you have a lower than normal amount of folic acid, a type of B vitamin, in your blood.

Deficiency - folic acid, Folic acid deficiency

Folic acid works with vitamin B12 and vitamin C to help the body break down, use, and make new proteins. The vitamin helps form red blood cells. It also helps produce DNA, the building block of the human body, which carries genetic information.

Folic acid is a type of B vitamin. It is water-soluble, which means it is not stored in the fat tissues of the body. Water-soluble vitamins dissolve in water. Leftover amounts of the vitamin leave the body through the urine.

Because folate is not stored in the body in large amounts, your blood levels of folate will get low after only a few weeks of eating a diet low in folate. You can get folate by eating green leafy vegetables and liver.

Causes of folate deficiency are:

• Diseases in which folic acid is not absorbed well, such as celiac disease (sprue) or Crohn's disease
• Drinking too much alcohol
• Eating overcooked food
• Getting too much folic acid during the third trimester of pregnancy
• Hemolytic anemia
• Medications, such as phenytoin (Dilantin), sulfasalazine, or trimethoprim-sulfamethoxazole
• Poor diet (often seen in the poor, the elderly, and people who do not eat fresh fruits or vegetables)

Folic acid deficiency may cause:

• Fatigue
• Gray hair
• Mouth sores (ulcers)
• Poor growth
• Swollen tongue

Folate deficiency can be diagnosed with a blood test. Pregnant women usually have such blood tests during prenatal checkups.

Complications include:

• Anemia (low red blood cell count)
• Low levels of white blood cells and platelets (in severe cases)

In folate-deficiency anemia, the red blood cells are abnormally large (megaloblastic).

Folic acid is also needed for the development of a healthy fetus. It plays an important part in the development of the fetus' spinal cord and brain. Folic acid deficiency can cause severe birth defects of the brain and spinal cord, known as neural tube defects.

The best way to get the daily requirement of all essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide plate. Most people in the United States eat enough folic acid because it is plentiful in the food supply.

Folate occurs naturally in the following foods:

• Beans and legumes
• Citrus fruits and juices
• Dark green leafy vegetables
• Liver
• Poultry, pork, and shellfish
• Wheat bran and other whole grains

The Institute of Medicine's Food and Nutrition Board recommends that adults get 400 micrograms of folate daily. Women who could become pregnant should take folic acid supplements to ensure that they get enough each day.

Specific recommendations depend on a person's age, gender, and other factors (such as pregnancy). Many foods now have extra folic acid added to help prevent birth defects.

See: Folic acid in diet for the full folic acid requirements by age group.

See: Folic acid and birth defect prevention for more information on folic acid requirements during pregnancy.

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Antony AC. Megaloblastic anemias. In: Hoffman R, Benz EJ Jr., Shattil SJ, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2008:chap 39.

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