Phytonadione is a type of vitamin K, specifically vitamin K1, and is found naturally in vegetables, especially in green leafy plants. It is also used as a dietary supplement and an antidote to anticoagulants such as warfarin. In biochemical terms, vitamin K1 is an essential component in the formation of blood clotting factors, which is why it acts as an effective antidote to blood thinners.
Tara Robinson (young Penelope Garcia) and Paget Brewster (Prentiss) both appear in The Witch Files (2018).
The EIS agent's name, Sara Freeman, is similar to the protagonist of the video game Half Life, Gordon Freeman. Gordon Freeman also primarily wears a hazmat suit in the game.