What dietary factor can contribute to increased INR levels?

The correct choice relates to the role of vitamin K in the coagulation cascade and its impact on INR (International Normalized Ratio) levels. Vitamin K is crucial for the synthesis of clotting factors II, VII, IX, and X in the liver. These factors are essential for the blood coagulation process. When there is a poor oral intake of vitamin K, the body has reduced levels of these clotting factors, which can lead to an increased INR. An elevated INR indicates a higher risk of bleeding as it reflects the anticoagulation status; therefore, insufficient vitamin K intake can contribute to higher INR levels.

In contrast, excessive potassium intake, high calcium intake, and red meat consumption do not have a direct impact on vitamin K levels or INR. Potassium primarily affects cardiac function, calcium influences bone health and coagulation in different contexts, and while red meat has various nutritional factors, none specifically relate to increasing INR directly. Understanding the relationship between dietary factors and INR is essential for managing patients on anticoagulation therapy effectively.