This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which vitamin is most likely to be deficient in patients on treatment with isoniazid : 
Select and explain. 
A. Vitamin B1, B. Vitamin B2, C. Vitamin B6, D. Vitamin B12
C: Vitamin B6
Answer: C: Vitamin B6 
Explanation: None