This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Tuberculosis, Subject name: Pharmacology
Patients on isoniazid which vitamin deficiency is more likely to be seen. 
Select and explain. 
A. Vitamin B9, B. Vitamin B12, C. Vitamin B6, D. Vitamin B3
C: Vitamin B6
Answer: C: Vitamin B6 
Explanation: Ans. (c) Vitamin B6Ref. KDT 6th ed. / 740-41* For patients who are on isoniazid; peripheral neuropathy is observed in 10-20% of patients given dosages greater than 5 mg/kg/d but is infrequently seen with the standard 300 mg adult dose.* Pyridoxine (Vit B6), 25-50 mg/d, is recommended for those with conditions predisposing to neuropathy, an adverse effect of isoniazid.* NOTE: Isoniazid as a single agent is also indicated for treatment of latent tuberculosis. The dosage is 300 mg/d (5 mg/kg/d) or 900 mg twice weekly for 9 months.