Vitamin K is a fat-soluble vitamin. The primary dietary source of Vitamin K is green leafy vegetables, such as spinach, cabbage, and kale. Other sources include cheese, liver, green tea, etc.
Vitamin K is not stored in the liver. Its synthesis and metabolism take place in the liver. Vitamin K helps in the coagulation of proteins, including Prothrombin, Clotting factors VII, IX, and X. These proteins help bind with calcium and are bound to the surfaces of phospholipids.
Deficiency of Vitamin K is common in liver disease patients, such as obstructive jaundice, cholestasis, hepatic stenosis, and liver cirrhosis, among others. This deficiency can result in bleeding, with hematuria (blood in the urine) being the first sign. The most common sites of bleeding are the gastrointestinal tract and the nose.
Uses of Vitamin K
- Dietary deficiency: It is very rare in adults; however, 5-10 mg/day can be given orally or parenterally.
- Prolongation of antimicrobial therapy.
- In cases of obstructive jaundice or malabsorption syndromes, 10 mg of Vitamin K can be administered intramuscularly or orally along with bile salts.
- Liver diseases such as cirrhosis and viral hepatitis can lead to insufficient Vitamin K synthesis due to hepatic cell dysfunction or damage. The absence of Vitamin K can impact blood clotting factors.
- Newborns, especially premature babies, have low levels of Vitamin K. The level of Vitamin K decreases a few days after birth, leading to deficiency. Therefore, it is recommended to administer 1 mg of Vitamin K intramuscularly to infants after birth or intramuscularly to the mother 4 to 13 hours before birth. This helps treat or prevent hemorrhage disorders. Vitamin K3 (Menadione) is not used for this purpose.
- Antidote for oral anticoagulants: Anticoagulants prevent coagulation. In the case of warfarin, the International Normalized Ratio (INR) should be monitored. If the INR increases significantly, there is a higher risk of bleeding. In such cases, Vitamin K can be administered orally or parenterally, and INR should be checked after waiting for 24 hours. The dose and route are determined by the INR.
- Prolonged use of salicylic acid therapy can reduce the level of prothrombin and result in bleeding. In this condition, Vitamin K is prophylactically administered.
Adverse effects of Vitamin K are generally rare and produce only mild side effects. Sever anaphylatic reactions are occurs on intravenous injection of emulsified formulation, so this route is not be used.
