Final answer:
Folic acid is a form of vitamin B9, crucial for preventing certain birth defects during pregnancy and being converted in the liver to its active form, tetrahydrofolic acid (THF).
Step-by-step explanation:
Folic acid is a form of vitamin B9 that is rarely found in foods but is often included in vitamin supplements and added during the fortification of food. During pregnancy, providing sufficient folic acid is essential to reduce the risk of neurological defects, including spina bifida, which results from a failure of the neural tube to close. The Food and Nutrition Board of the Institute of Medicine recommends that all women who might become pregnant consume at least 400 µg/day of folate from supplements or fortified foods. Folic acid undergoes reduction in the liver to tetrahydrofolic acid (THF), the active coenzyme form, which is crucial for various metabolic processes including the synthesis of DNA and RNA.