Folinic Acid, also known as leucovorin, is a form of vitamin B9 that helps the body produce and maintain new cells. It is often used in medical treatments to reduce the side effects of certain chemotherapy drugs, particularly in patients receiving methotrexate. Folinic acid can enhance the effectiveness of some medications by providing a source of folate that cancer cells need to grow. In addition to its use in cancer treatment, folinic acid is also important in treating megaloblastic anemia, a condition caused by a deficiency of folate or vitamin B12. It can help restore normal blood cell production and improve overall health. Folinic acid is available in various forms, including oral tablets and injectable solutions.