Folic acid, also known as vitamin B9, is found naturally in certain foods. Folic acid is a synthetic folate that is added to foods such as bread and cereals to fortify them. Folate deficiency occurs when the amount of vitamin B9 in the body is very low.

Folic acid plays an important role in many of the body’s major functions, including building new proteins, producing DNA, forming red and white blood cells, and promoting tissue growth and cell production.

People with folate deficiency can experience symptoms such as fatigue, irritability, diarrhea, and increased heart rate, as well as complications such as anemia (low red blood cells) and ulcers. Pregnant women with folic acid deficiency may have an increased risk of certain birth defects.

Symptoms of folic acid deficiency include:

• Fatigue; weakness.pale
• irritability; forgetfulness
• diarrhea
• smooth and painful tongue or mouth
• Swelling of the tongue (glossitis)
• early gray hair
• headache
• palpitations
• shortness of breath
• Changes in skin, hair, and nails

Folate is found in a variety of foods, including beef liver, dark green leafy vegetables (such as broccoli and spinach), eggs, beans, peas, and certain fruits (such as bananas and avocados). Other foods are fortified with folic acid, especially grains such as bread, rice, cereals, and pasta.

If you don’t eat enough folate or folate-rich foods, or if your body doesn’t absorb enough folate, you can develop folate deficiency. This can occur for various reasons. Certain digestive disorders, excessive alcohol consumption, dietary changes, and side effects of medications such as dilantin (phenytoin) and azulfidine (sulfasalazine) can all interfere with nutrient uptake or absorption. Pregnant people need more folic acid than normal and are more likely to develop folic acid deficiency.

Risk factor

Several factors can increase the likelihood of developing folate deficiency, including:

• Eat a diet low in fruits and vegetables
• Eating overcooked produce frequently
• Conditions that affect your ability to absorb nutrients, such as celiac disease or inflammatory bowel disease (IBD)
• Alcohol use disorder (AUD)
• Kidney disease requiring dialysis
• Hemolytic anemia (increased destruction of red blood cells, causing deficiency)
• pregnancy
• Certain mutations in the methylenetetrahydrofolate reductase (MTHFR) gene
• senior citizen

Folic acid deficiency is diagnosed with a simple serum (blood) test. If you have associated symptoms, your health care provider may order a blood test for folate deficiency. During pregnancy, you may be tested for folate deficiency during your regular prenatal checkup.

Your health care provider may also recommend a complete blood count (CBC) or bone marrow test if you suspect you are developing folate deficiency anemia.

The main treatment for folate deficiency is folic acid supplementation. It can be taken orally or by injection if needed. If your symptoms are severe, you may need intravenous (IV) folic acid.

If you have an underlying cause of folate deficiency, such as Crohn’s disease, it is important to follow your health care provider’s recommendations to effectively treat the underlying condition.

The best way to prevent folate deficiency is to get enough folate through your diet or through dietary supplements containing folic acid. Foods such as beef liver, spinach, mustard greens, asparagus, Brussels sprouts, oranges, peas, and green beans are especially rich in folate.

Folic acid is found in various multivitamins in the form of folic acid. If you’re pregnant, your health care provider is likely to recommend a prenatal vitamin that contains folic acid.

The recommended daily amount of folic acid depends on your age and whether you are pregnant or breastfeeding. The daily intake amount, expressed in micrograms (mcg) of dietary folate equivalents (DFE), is as follows:

• Until 6 months old: 65mcg DFE
• Infants up to 12 months: 80mcg DFE
• Children 1-3 years old: 150mcg DFE
• Children aged 4-8: 200mcg DFE
• Children aged 9-13: 300mcg DFE
• Teens ages 14-18: 400μg DFE
• Adults 19 years and older: 400μg DFE
• Pregnant: 600mcg DFE
• Breastfeeding: 500mcg DFE

If left untreated, folate deficiency can lead to several health complications. These include:

• Low numbers of red blood cells, white blood cells, and platelets
• Megaloblastic anemia with enlarged red blood cells
• Ulcers, especially in the mouth and tongue
• depression
• Increased risk of stroke and heart disease due to elevated levels of an amino acid called homocysteine
• dementia

When a pregnant person experiences folate deficiency anemia, there is an increased risk of birth defects in the fetus and birth complications such as:

• premature birth
• Neural tube defects such as spina bifida
• fetal growth restriction
• low birth weight baby

Folic acid, or vitamin B9, is also called folic acid. Found in foods such as liver, leafy vegetables, eggs, legumes, fruits, and fortified grains. If you don’t get enough folate in your diet or can’t absorb it properly, you can develop folate deficiency. This can lead to folate deficiency anemia, which causes symptoms such as fatigue, irritability, a swollen tongue, and increased heart rate.

If you think you may have a folic acid deficiency, ask your health care provider about taking a supplement containing folic acid.