Some substances you consume, such as alcohol, can affect the
PT/
INR test. Some antibiotics can increase the
PT/
INR. Barbiturates and vitamin K - either in a multivitamin or liquid nutrition supplement - can decrease PT.
Certain foods (such as beef and pork liver, green tea, broccoli, chickpeas, kale, turnip greens, and soybean products) contain large amounts of vitamin K and can alter PT results.
The vitamins you are taking could be the cause of your PT INR being a fraction low.