Final answer:
The need for additional teaching is shown by the client's intent to include green leafy vegetables in her diet, which are rich in vitamin K and can counteract anticoagulant therapy, such as warfarin.
Step-by-step explanation:
The client's statement that indicates the need for additional teaching is "I'll include green leafy vegetables in my diet." Anticoagulant therapy, such as warfarin, can be affected by diet, particularly by foods high in vitamin K, which is a key factor in blood clotting. Green leafy vegetables are rich in vitamin K, and therefore, their consumption can counteract the effectiveness of the anticoagulant medication. The client should be advised to maintain a consistent intake of vitamin K while on anticoagulant therapy and to communicate with her healthcare provider to manage and monitor her diet and medication dosage appropriately.