What is the correct description of Vitamin K (Vitamin K)?

Vitamin K Characteristics

Vitamin K is a fat-soluble vitamin that requires bile salts for absorption. 1

Key Properties of Vitamin K

• Fat Solubility: Vitamin K is classified as a fat-soluble vitamin, not water-soluble 1, 2. This means it:

  • Is stored in fatty tissue and the liver
  • Requires bile salts for proper absorption in the intestine
  • Can accumulate in the body, unlike water-soluble vitamins

• Absorption Site: Vitamin K is absorbed in the small intestine, specifically requiring bile salts for its absorption 1. This is consistent with other fat-soluble vitamins that require bile for micelle formation and absorption.

• Role in Coagulation: Vitamin K is essential for the synthesis of several coagulation factors, but importantly:

  • It is NOT required for factor V synthesis 3
  • It IS required for factors II, VII, IX, and X, as well as proteins C and S 3

Clinical Significance

The fat-soluble nature of vitamin K has important clinical implications:

• Malabsorption Conditions: Patients with conditions causing steatorrhea (fat malabsorption) are at high risk for vitamin K deficiency 1

  • This includes celiac disease, cystic fibrosis, short bowel syndrome, and other conditions affecting fat absorption

• Anticoagulant Interactions: Vitamin K intake affects the response to vitamin K antagonists like warfarin 1

  • Patients on anticoagulants need to maintain consistent vitamin K intake
  • Continuous enteral nutrition should be withheld 1 hour before and after anticoagulant administration

• Deficiency Manifestations: Vitamin K deficiency can lead to:

  • Bleeding disorders due to impaired clotting factor synthesis
  • Poor bone development and osteoporosis
  • Increased cardiovascular disease risk 1

Monitoring and Supplementation

• Vitamin K status should be assessed in patients with:

  • Fat malabsorption disorders
  • Prolonged antibiotic use
  • Chronic kidney disease 1

• For vitamin K deficiency treatment:

  • IV administration has maximum effect in 6-12 hours
  • Oral supplementation takes about 24 hours to reach maximum effect 1

In summary, vitamin K is a fat-soluble vitamin that requires bile salts for absorption in the small intestine and is crucial for the synthesis of several coagulation factors (but not factor V).