Which vitamin deficiency is most commonly seen in a pregnant mother who is on phenytoin therapy for epilepsy:
Hypotension and arrythmias occur only on iv injection.
Vitamin deficiencies associated with phenytoin: — Folic acid (most common)

– Vitamin D
– Vitamin K
These 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.
Vitamin B6
Vitamin B12
Vitamin A
Folic acid