Folic acid plays an essential role in cell multiplication and is critical in DNA and RNA formation, and is therefore especially important in foetal development. It is now widely accepted and established that lack of folate during the first trimester of pregnancy increases the risk of neural tube defects in the developing baby. Folic acid in also known to play an important part in the body's regulation of homocysteine, the amino acid like compound that is implicated in the damage that occurs to the lining of blood vessel walls that can then lead to the build up of plaques.

Folic acid is a water soluble vitamin which the body cannot store for long. Good food sources include green vegetables and whole grains. However cooking and storage can deplete the levels in food and currently 47% of women fail to consume the NRV of 200µg/day, which is why supplementation is recommended. Bioavailability studies indicate that folic acid supplements are well absorbed and are a reliable way to guard against dietary deficiencies.
A large intake of folic acid may mask the signs and symptoms of Vitamin B12 deficiency (Pernicious Anaemia).