(PIVKA) (prō'tēn in-dūst' vī'tă-min ab'sĕns) Nonfunctional protein precursors of the prothrombin group of coagulation factors (e.g., factors II, VII, IX, X). They are synthesized in the liver in the absence of vitamin K and lack the carboxyl (COOH-) group needed to bind the factor to a phospholipid surface.