A 66-year-old man is a long-time client of the PMHNP. He has been taking several vitamins under the supervision of the provider. Recently, he had a transient ischemic attack (TIA) and was placed on warfarin (Coumadin). Which of the following vitamins or supplements will the client need to discontinue?

Choice A reason: L-methyl folate does not significantly affect coagulation or interact with warfarin and can usually be continued safely. Choice B reason: Vitamin D3 has no major interaction with warfarin and does not influence clotting, so it is generally safe to continue. Choice C reason: Melatonin may have minimal effects on blood pressure or sedation but does not interfere with warfarin metabolism. Choice D reason: Vitamin E has anticoagulant properties and can increase the risk of bleeding when combined with warfarin. Discontinuation is recommended to reduce hemorrhagic risk.