<prompt> Which vitamin deficiency is most commonly seen in a pregnant mother who is on phenytoin therapy for epilepsy:Vitamin B6Vitamin B12Vitamin AFolic acid  <response>: Hypotension and arrythmias occur only on iv injection.Vitamin deficiencies associated with phenytoin: Folic acid most common Vitamin D Vitamin KThese vitamin deficiencies occur in all patients an phenytoin therapy and have nothing do with pregnancy. Hence all patients on phenytoin are advised to take folic acid supplementation. 