First discovered in the 1940s, folate (also known as folic acid or folacin) is one of 8 vitamins of the B group . Once referred to as vitamin B9, it is crucial for several steps in the synthesis of the genetic material DNA. When it is in short supply, the nuclei of cells cannot make new DNA and thus cells cannot divide and multiply properly. Growth then stops or is distorted. Rapidly-dividing cells such as those that make up the neural tube need folate in plentiful supply.