Folic acid deficiency means that there is a lower than normal amount of folic acid in your blood. Folic acid is a vitamin also called B9. It does not store well in the body. You must get a regular supply of it through your diet.

Folic acid (B9) plays a role in:

  • Building proteins in the body
  • Producing DNA
  • Helping to form red blood cells

Scanning Electron Micrograph of Red Blood Cells

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Folic acid deficiency may be caused by one or more of the following:

  • Not having enough folic acid in your diet
  • Poor absorption of folic acid through your intestine
  • Greater need for folic acid—most often due to pregnancy
  • Medical treatment or medicine that is blocking absorption or increasing need


Many different conditions or habits can affect folic acid levels:

  • Factors that lead to poor intake include:
    • Limited consumption of fresh, minimally cooked food
    • Long-term need for IV nutrition (total parenteral nutrition)
    • Alcoholism
  • Conditions that can lead to poor absorption include:
    • Inflammatory bowel disease
    • Celiac disease or other malabsorption disorders
    • Certain medications, such as anticonvulsants and oral contraceptives
    • Bariatric surgery
  • Increased need for folic acid because of:
    • Pregnancy or breastfeeding
    • Infancy
    • Cancer
  • Liver disease
  • Chronic hemolytic anemia
  • Kidney dialysis
  • Certain medicine, such as methotrexate
  • Elevated homocysteine levels in the blood


Folic acid deficiency may cause:

  • Fatigue
  • Poor appetite
  • Headache
  • Pale skin
  • Red, irritated, swollen, and sometimes shiny tongue
  • Mouth ulcers
  • Shortness of breath and lightheadedness
  • Change in bowel patterns, usually diarrhea

Complications from folic acid deficiency include:

  • Megaloblastic anemia—a blood disorder characterized by larger than normal red blood cells
  • Elevated homocysteine levels in the blood—a risk factor for heart disease
  • Neural tube defects that affect fetal spinal cord, brain, and skull development


You will be asked about your symptoms and health history. A physical exam will be done. A blood test will show vitamin B levels. However, this may be due to other conditions. Red blood cell folate levels will also need to be tested. This will confirm folic acid problems.

It is important to confirm a diagnosis before treatment begins.


A folic acid supplement is often the first step. It can increase the folic acid in the body. Related conditions may also need treatment. It may help to improve the absorption of folic acid.

It will take some time for red blood cells to return to normal. The anemia will usually be cured within 2 months.


To get enough folate in your diet, consume plenty of the following foods:

  • Fortified grains, cereals, and bread products
  • Dried beans and legumes
  • Poultry, pork, liver, and shellfish
  • Eggs
  • Fresh fruits and vegetables, especially dark, leafy green vegetables, and citrus fruits and juices

If you have a condition that increases your risk of folic acid deficiency:

  • Follow treatment plan to manage your condition.
  • Work with your doctor or a dietitian to see if diet changes may help.