supplement with phenytoin

Q: Which of the following supplement should be prescribed with phenytoin?

A) Vtamin C
B) Vitamin B6
C) Vitamin B9
D) Vitamin B12
E) Vitamin D


Answer: C

Vitamin B9 is Folic acid!

Phenytoin causes folic acid depletion in the body. Folic acid is not stored in the body in large amounts, and blood levels get low very quickly, resulting in signs and symptoms of folate deficiency like gingival hypertrophy.

#pharmacology


Reference: 

Arya R, Gulati S, Kabra M, et al. Folic acid supplementation prevents phenytoin-induced gingival overgrowth in children. Neurology 2011; 76:1338.