Definition

Folic acid deficiency is a condition in which the body lacks adequate stores of the B vitamin folic acid. This vitamin plays a role in building proteins in the body, including blood cells. Lack of folic acid leads to a type of blood disorder called megaloblastic anemia .

There are many types of anemia . Megaloblastic anemia is mainly characterized by larger than normal red blood cells in the blood. Folic acid deficiency is only one of several causes of megaloblastic anemia. Therefore, it is important for your doctor to confirm that folic acid deficiency is the cause of the megaloblastic anemia. After doing so, this condition can easily be treated. Contact your doctor if you think you may have a folic acid deficiency.

Scanning Electron Micrograph of Red Blood Cells

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Causes

There are several causes of folic acid deficiency, including the following:

  • Inadequate dietary intake of folic acid due to:
    • Limited consumption of fresh, minimally cooked food
    • Chronic alcoholism
    • Long-term need for intravenous nutrition (total parenteral nutrition)
  • Inadequate absorption of folic acid due to:
    • Malabsorption syndromes, such as celiac disease
    • Drug interactions, such as anticonvulsant medications and oral contraceptives
  • Increased need for folic acid due to:
    • Pregnancy
    • Lactation
    • Infancy
    • Malignancy (eg, cancer )
  • Increased loss
    • Hemodialysis
  • Impaired use

Risk Factors

The following risk factors increase your chance of developing a folic acid deficiency. Tell your doctor if you are concerned you have an increased need for folic acid due to the following conditions:

  • Pregnancy or lactation (breastfeeding)
  • Malignancy
  • Liver disease
  • Alcoholism
  • Chronic hemolytic anemia
  • Kidney dialysis treatment
  • Celiac disease or other malabsorption syndromes
  • Need for certain medications such as anticonvulsants and oral contraceptives
  • Elevated homocysteine levels in the blood

Symptoms

If you experience any of these symptoms, do not assume it is due to folic acid deficiency. These symptoms may be caused by other, more serious health conditions. If you experience any one of them, see your physician.

  • Fatigue
  • Headache
  • Pallor (pale skin)
  • Red, irritated, sometimes shiny tongue
  • Shortness of breath and dizziness
  • Change in bowel pattern ( diarrhea usually)
  • Elevated level of homocysteine in the blood (a heart disease risk factor)

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam. He or she will also perform simple blood tests to confirm a diagnosis of megaloblastic anemia, and most importantly, determine the cause of the anemia.

It is difficult to distinguish between folic acid deficiency and vitamin B12 deficiency . Both deficiencies result in megaloblastic anemia. However, folic acid deficiency is confirmed only by measuring red blood cell (RBC) folate levels in the blood.

It is especially important to confirm a diagnosis of folic acid deficiency before treatment with supplemental folic acid begins. Mistreating an actual vitamin B12 deficiency with supplemental folic acid will mask the vitamin B12 deficiency, meaning the anemia will be corrected, but the neurological damage associated with vitamin B12 deficiency will progress.

Blood tests may include the following:

  • Hemoglobin—will be lower than normal if any type of anemia is present
  • Mean corpuscular volume (MCV)—measures the size of the red blood cell and will be larger than normal if folic acid deficiency is present
  • Color of the red blood cell—will be normal if folic acid deficiency is present
  • Serum folic acid—values of less than 5 ng/mL suggest a folic acid deficiency
  • Red blood cell (RBC) folate—low levels confirm a diagnosis of folic acid deficiency

Treatment

Talk with your doctor about the best treatment plan for you. Treatment options include the following:

Vitamin Supplementation

Folic acid deficiency is usually treated with 1,000 micrograms of supplemental folic acid, given once a day until folic acid levels are replenished. The anemia usually is corrected within two months.

Prevention

Once a folic acid deficiency is corrected, it is usually possible to consume enough folic acid by eating a balanced, varied diet including rich sources of folate, the food form of folic acid. The recommended dietary allowance (RDA) for folic acid is 400 micrograms per day for most adults.

To help reduce your chances of getting folic acid deficiency, consume plenty of the following foods:

  • Fortified grains, cereals, and bread products
  • Dried beans and legumes
  • A variety of fresh fruits and vegetables, specifically:
    • Dark, green leafy vegetables such as spinach, lettuce, asparagus, and broccoli
    • Oranges and orange juice