Below you can find the Vitamin k is essential for the synthesis of prothrombin which helps blood do this Jeopardy Words Answer. The answer to Vitamin k is essential for the synthesis of prothrombin which helps blood do this has 4 letters. This clue belongs to the Biology category and is part of Jeopardy Word Level 1803. If you scroll near the bottom you will find other clues and answers part of level 1803