was ist vitamin k3 — what symptoms are typical?

Vitamin K3 (menadione) is a synthetic form of vitamin K not recommended for human consumption. Unlike natural K1 (phylloquinone) and K2 (menaquinone), K3 can cause oxidative stress and is associated with toxicity including hemolytic anemia, liver damage, and allergic reactions. Typical symptoms of overdose include jaundice, anemia, and elevated liver enzymes. Deficiency of vitamin K (any form) manifests as prolonged bleeding time, easy bruising, and in severe cases internal bleeding. Since K3 is rarely used in human supplements, poisoning cases are uncommon. The evidence is mostly mechanistic and from animal studies. If vitamin K imbalance is suspected, a physician should be consulted to check coagulation parameters (INR) and liver function.