Vitamin K1 is used to prevent and treat bleeding caused by vitamin K deficiency. Functions include bleeding caused by obstructive jaundice, biliary fistula, chronic diarrhea, etc., hypoprothrombinemia caused by coumarins, salicylates, etc., neonatal bleeding, and vitamin K deficiency caused by long-term application of broad-spectrum antibiotics. Vitamin K is necessary for the synthesis of factors II, VII, IX and X by the liver. Vitamin K deficiency can cause impaired or abnormal synthesis of these coagulation factors, which can be seen in bleeding tendency and prolonged prothrombin time. The efficacy of this product is not obvious in patients with hepatic impairment, and blindly increasing the dosage may aggravate the hepatic impairment. This product is ineffective against heparin-induced hemorrhagic tendency. Vitamin K1 decomposes rapidly when exposed to light and should be protected from light during use. Vitamin K1 dosage is recommended to follow the doctor’s instructions to avoid delay.