Vitamin B9 (Folic Acid)


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Vitamin B9, also known as folate or folic acid, is a water soluble vitamin. Folate is is naturally found in foods, while folic acid is a synthetic supplement.


Vitamin B9 has many functions in the body including:

  • Working as a coenzyme in the metabolism of nucleic and amino acids
  • Assisting in vitamin B12 and C use and breakdown
  • Assisting in the formation of new proteins
  • Helping with red blood cell formation and circulation.

Note: Folate is probably best known for its role in pregnancy, helping to prevent neural tube defects, and thus is given in prenatal vitamins.

Food Sources

Vitamin B9 can be found in several foods including:


Common symptoms and resulting conditions of vitamin B9 deficiency include:

  • Anemia (macrocytic or megaloblastic)
  • Leukopenia
  • Thrombocytopenia
  • Weakness
  • Weight loss
  • Cracking and redness of tongue and mouth
  • Diarrhea
  • Low birth weight and preterm delivery in pregnancy
  • Neural tube defects in newborns.

However, your individual response could be different. If you suspect a health problem or deficiency in certain nutrients, please see your primary health care provider (doctor, naturopath, etc). They can help unravel the complexity of your physiology.


There are currently no known symptoms of vitamin B9 excess/toxicity.


For recipes rich in B9, check out any of the Encyclopedia of Food entries for food items listed above!

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At a Glance

Vitamin B9, also known as folate, has many important functions in the body. It helps metabolize nucleic and amino acids, assists in the formation of new proteins, helps with red blood cell formation, and more. Vitamin B9 can be found in beans, citrus fruits, whole grains, and green leafy vegetables.