menadione

Synthetic vitamin K3 (menadione, often listed as menadione sodium bisulfite complex) can cause hemolysis and liver strain at high doses, so some owners prefer to avoid it. However, inclusion levels in pet food are low: in 2021 AAFCO adopted an expert panel recommendation that it is a safe source of vitamin K when used under good manufacturing practices, and cat foods high in fish are actually required to include it. It is a debated ingredient you may choose to avoid — not a poison.

Other common names: menadione sodium bisulfite, menadione sodium bisulfite complex, menadione dimethylpyrimidinol bisulfite, vitamin K3, synthetic vitamin K, 合成維生素K3, メナジオン