This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
Folate deficiency occurs due to 
Select and explain. 
A. Phenytoin, B. Phenbarbitone, C. Primidone, D. All
D: All
Answer: D: All 
Explanation: Phenytoin , phenobarbitone and primidone(metabolized to phenobarbitone in body ) causes megaloblastic anemia as phenytoin decreases absorption and increases excretion of folate ref KD TRIPATHI 8TH ED.