OVERVIEW

What are the sources of vitamin K in the human body?

Vitamin K1 comes from food, mainly green vegetables such as spinach and broccoli. Vitamin K2 is synthesized by microorganisms in the human intestines.

What is vitamin K deficiency?

Vitamin K deficiency is a disease state caused by insufficient vitamin K in the body. The main symptoms include easy bleeding, such as skin bruising, gum bleeding, nosebleeds, dark stools, red urine, and subungual linear hemorrhages.

Vitamin K deficiency is very rare in healthy adults. It only occurs under certain conditions, such as the use of specific antibiotics and anticoagulants, long-term reliance on intravenous nutrition without eating, or diseases of the liver, gallbladder, or pancreas. Additionally, newborn infants are also prone to vitamin K deficiency.

SYMPTOMS

What are the symptoms of vitamin K deficiency?

The main manifestation is various types of bleeding.

Common symptoms include skin petechiae and ecchymoses, nosebleeds, gum bleeding, black stools, hematuria, menorrhagia, hemorrhoid bleeding, and postoperative wound oozing. Internal hematomas and joint cavity bleeding are relatively rare. Occasionally, intracranial hemorrhage may occur, which can be life-threatening.

CAUSES

What are the causes of vitamin K deficiency?

• Inadequate vitamin K intake: Such as prolonged starvation or inability to eat normally due to illness.
• Poor vitamin K absorption and insufficient endogenous synthesis: Seen in patients with liver, biliary, pancreatic, or intestinal diseases, such as cystic fibrosis, primary biliary cirrhosis, primary sclerosing cholangitis, biliary atresia, familial intrahepatic cholestasis, active celiac disease, inflammatory bowel disease, short bowel syndrome, etc.
• Impaired vitamin K utilization: Occurs in individuals with severe liver dysfunction or those taking certain medications (e.g., antibiotics, warfarin). Although these individuals have sufficient vitamin K, it cannot function properly.
• Neonatal vitamin K deficiency bleeding (VKDB): Caused by maternal use of certain medications before delivery (e.g., anticonvulsants, anticoagulants, antituberculosis drugs), immature neonatal intestinal function, antibiotic treatment for infections in newborns, or low vitamin K content in breast milk. It manifests as bleeding in various parts of the body.

DIAGNOSIS

What tests are needed to diagnose vitamin K deficiency?

Direct measurement of vitamin K levels in the blood is difficult to perform in most hospitals. Indirect diagnosis of vitamin K deficiency can be made by checking blood counts, coagulation function, clotting factors, and protein induced by vitamin K absence or antagonist-II (PIVKA-II).

Test results for patients with vitamin K deficiency are as follows:

• Prolonged prothrombin time (PT) and elevated international normalized ratio (INR);
• Decreased clotting factors II, VII, IX, and X;
• Elevated PIVKA-II;
• Normal thrombin time (TT), fibrinogen (Fg), and platelet count.

Which diseases have similar manifestations to vitamin K deficiency?

Many diseases can cause bleeding and need to be differentiated from vitamin K deficiency.

• Platelet abnormalities: Such as immune thrombocytopenic purpura, aplastic anemia, leukemia, and disseminated intravascular coagulation. These conditions show low platelet counts, whereas vitamin K deficiency has normal platelets.
• Vascular abnormalities: Such as Henoch-Schönlein purpura, poisoning, or vitamin C deficiency. These diseases usually have specific medical histories, with normal platelet counts and coagulation function, whereas vitamin K deficiency shows abnormal coagulation.
• Coagulation disorders: Such as hemophilia, liver disease, or excessive anticoagulant use. These can be distinguished from vitamin K deficiency by reviewing family history, medical history, and medication use.
• Gastrointestinal ulcers or tumors: May cause hematemesis or melena. These conditions usually have normal platelet counts and coagulation function, and abnormalities can be detected via gastroscopy.
• Urinary tract infections or bladder tumors: May cause hematuria. These conditions typically have normal platelet counts and coagulation function and can be differentiated from vitamin K deficiency through urinalysis, urine culture, tumor markers, or urinary system ultrasound.

TREATMENT

Which department should I visit for vitamin K deficiency?

Hematology or Nutrition Department. Patients with severe bleeding should go to the Emergency Department.

How is vitamin K deficiency treated?

• Vitamin K supplementation: Can be administered orally, intramuscularly, subcutaneously, or intravenously.
• Hemostasis: For severe bleeding or neonatal vitamin K deficiency bleeding, plasma transfusion or prothrombin complex concentrate may be used to stop bleeding.
• Treat the underlying cause: Address conditions such as hepatobiliary or pancreatic diseases, adjust anticoagulant dosage, switch antibiotics, or supplement vitamin K for breastfeeding mothers.

What are the side effects of vitamin K deficiency treatment drugs?

When dosed appropriately, vitamin K generally has no side effects. Overdose or toxicity is very rare. Excessive vitamin K in newborns may cause hemolytic anemia and jaundice.

Does vitamin K deficiency require hospitalization?

Hospitalization is necessary if severe bleeding symptoms occur.

Can vitamin K deficiency be completely cured? Will it recur? How to prevent recurrence?

It can be fully cured. Recurrence is possible. Prevention methods are essentially the same as above.

Can vitamin K deficiency lead to death?

If massive bleeding or intracranial hemorrhage occurs and treatment is delayed, it may be fatal.

DIET & LIFESTYLE

What should patients with vitamin K deficiency pay attention to in daily life?

Move slowly and gently to avoid bumps or falls, which may lead to prolonged bleeding.

What should patients with vitamin K deficiency pay attention to in their diet?

Eat more green vegetables. However, patients taking warfarin have special dietary requirements—consult a doctor for details.

Food should be soft and residue-free to prevent prolonged bleeding from digestive tract injuries.

Does vitamin K deficiency affect fertility?

Yes, it affects female fertility because patients with vitamin K deficiency are prone to bleeding, making pregnancy high-risk. It is advised to conceive after treatment.

Does vitamin K deficiency affect daily activities like exercise or travel?

Yes. Due to the risk of bleeding, patients should avoid strenuous exercise or long-distance travel. It is recommended to resume such activities after recovery.

PREVENTION

Is there a way to prevent vitamin K deficiency?

Yes, there are preventive measures.

• People with hepatobiliary, pancreatic, or intestinal diseases, long-term inability to eat normally, or liver diseases should take preventive vitamin K supplements.
• Those taking anticoagulant medications (such as warfarin) should regularly check their coagulation function at the hospital and adjust their medication dosage.
• To prevent neonatal hemorrhagic disease: Women who have taken warfarin, cephalosporins, or antiepileptic drugs during pregnancy should supplement with vitamin K in the last 3 months of pregnancy and before delivery; all newborns should receive an intramuscular injection of vitamin K after birth; exclusively breastfed infants should have their mothers supplement with vitamin K.