Obstetrics & Gynaecology – MCQ 63 – Phenytoin in pregnancy

Which vitamin deficiency is most commonly seen in a pregnant mother who is on phenytoin therapy for epilepsy?
A. Vitamin B6
B. Vitamin B12
C. Vitamin A
D. Folic acid

Correct answer : D. Folic acid

Folic acid absorption is decreased and its excretion is increased in those using phenytoin. Other vitamin deficiencies seen in phenytoin users : Vitamin D, Vitamin K. Hence pregnant woman on phenytoin should take folic acid, cholecalciferol and phytonadione supplements.