Gynaecology & Obstetrics During pregnancy, deficiency of which vitamin in women causes neural tube defect in the newborn: March 2010 A Thiamine B Pyridoxine C Folic acid D Cyanocobalamin 💡 Explanation During pregnancy, deficiency of which vitamin in women causes neural tube defect in the newborn: March 2010 ✓ Correct Answer: C. Folic acid