Folate is a form of B vitamin that occurs naturally in many foods. Folic acid is the man-made form of folate that is added to processed foods or vitamin and mineral supplements. Folate is needed in the human body for production of red blood cells.A lack (deficiency) of folate in the human body can be caused by certain diseases, by taking certain medications, or by not getting enough folate in your diet. Folate deficiency can lead to decreased red blood cells, or anemia. Folate deficiency can also cause high levels of a certain amino acid in the blood, a condition called hyperhomocysteinemia (HYE-per-HOE-moe-sis-tin-EE-mee-a).L-methylfolate is a medical food for use in people who have conditions related to folate deficiency. L-methylfolate is also used in people with major depressive disorder who have folate deficiency, or in people with schizophrenia who have hyperhomocysteinemia related to folate deficiency.L-methylfolate is not an antidepressant or anti-psychotic medication. However, l-methylfolate may enhance the effects of antidepressant medications.