病人開始服用 Warfarin，護理師應強調哪項飲食建議？
A client is started on warfarin therapy. Which instruction should the nurse emphasize regarding dietary choices?
- AMaintain a consistent intake of vitamin K✓ 正解維持維生素K攝取量一致
- BRestrict intake of high-protein foods限制高蛋白質食物攝取
- CIncrease intake of cranberry juice增加蔓越莓汁攝取
- DAvoid all green leafy vegetables避免所有深綠色葉菜
Warfarin 的主要機轉是透過拮抗維生素 K（Vitamin K）依賴性凝血因子（II, VII, IX, X）的合成來發揮抗凝血作用。臨床上，飲食中維生素 K 的攝取量會直接影響 Warfarin 的抗凝血效果（以 INR 值監測）。若病人攝取量忽高忽低，INR 值會隨之波動，導致抗凝血效果不穩定。因此，護理教學的重點在於「規律性」而非「禁止」，確保體內維生素 K 水平恆定，使 INR 維持在治療範圍內。
The principal mechanism of warfarin is to exert anticoagulant effect by antagonizing the synthesis of vitamin K-dependent clotting factors (II, VII, IX, and X). Clinically, the amount of vitamin K in the diet directly affects warfarin's anticoagulant effect (monitored by INR). If the patient's intake fluctuates widely, INR will fluctuate accordingly, leading to unstable anticoagulation. Therefore, the focus of nursing teaching is "consistency" rather than "prohibition," maintaining stable vitamin K levels in the body so that the INR remains within the therapeutic range.