Díaz Lab Testing Store › Vitamin K1 | Plasma (Quest) Image 1 of 1 Vitamin K1 | Plasma (Quest) $77.00 Vitamin K1 is primarily responsible for helping your blood clot properly to prevent excessive bleeding. Add To Cart Added! Vitamin K1 is primarily responsible for helping your blood clot properly to prevent excessive bleeding. Add-on | Interpretation for Individual Markers $17.00 Add Added!