Role of Vitamin K in coagulation

Last updated: July 09, 2022

Role of Vitamin K in coagulation

MPAN 690 Week 4 - Hematology

MPAN 690 Week 4 - Hematology

Approach to anemia (underproduction): Clinical sciences
Approach to anemia (destruction and sequestration): Clinical sciences
Macrocytic anemia: Pathology review
Microcytic anemia: Pathology review
Sideroblastic anemia
Aplastic anemia
Autoimmune hemolytic anemia
Non-hemolytic normocytic anemia: Pathology review
Iron deficiency anemia
Anemia of chronic disease
Fanconi anemia
Megaloblastic anemia
Anemia in pregnancy: Clinical sciences
Iron deficiency anemia: Clinical sciences
Anemia of chronic disease: Year of the Zebra
Diamond-Blackfan anemia
Intrinsic hemolytic normocytic anemia: Pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Pernicious anemia: Year of the Zebra
Iron deficiency and iron deficiency anemia (pediatrics): Clinical sciences
Approach to bleeding disorders (thrombocytopenia): Clinical sciences
Platelet disorders: Pathology review
Immune thrombocytopenia
Heparin-induced thrombocytopenia
Immune thrombocytopenia: Clinical sciences
Thrombotic thrombocytopenic purpura
Coagulation disorders: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Approach to bleeding disorders (coagulopathy): Clinical sciences
Coagulation (secondary hemostasis)
Disseminated intravascular coagulation
Approach to bleeding disorders (platelet dysfunction): Clinical sciences
Disseminated intravascular coagulation: Clinical sciences
Role of Vitamin K in coagulation
Leukemias: Pathology review
Acute leukemia
Chronic leukemia
Approach to leukemia: Clinical sciences
Lymphomas: Pathology review
Hodgkin lymphoma
Non-Hodgkin lymphoma
Approach to lymphoma: Clinical sciences
Myeloproliferative disorders: Pathology review
Polycythemia vera (NORD)
Approach to myeloproliferative neoplasms: Clinical sciences

Transcript

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Vitamin K helps to regulate the process of blood coagulation by assisting in the conversion of certain coagulation factors into their mature forms. Without vitamin K, our bodies would be unable to control clot formation. Imagine being unable to form blood clots effectively--that would mean that we would lose all of our blood volume from something as simple as a pinprick! To prevent this extreme scenario - vitamin K must be ingested, metabolized, and utilized to create mature coagulation factors.

Now, to understand the regulation of clot formation, we first need to talk briefly about hemostasis, in which hemo refers to the blood, and stasis means to halt or stop. Hemostasis is divided into two phases: primary and secondary hemostasis. Primary hemostasis involves the formation of a platelet plug around the site of an injured blood vessel, and secondary hemostasis reinforces the platelet plug with the creation of a protein mesh called fibrin. To get to fibrin, a set of coagulation factors, each of which are enzymes, need to be activated. These enzymes are activated via a process called proteolysis- which is where a portion of the protein is clipped off. In total, there are twelve coagulation factors numbered factors I-XIII, there’s no factor VI. Most of these factors are produced by liver cells, and it turns out that producing coagulation factors II, VII, IX, and X requires an enzyme that uses vitamin K.

Vitamin K is found in abundance in green leafy foods—things like spinach, kale, and chard which all have high concentrations of vitamin K. It’s a fat-soluble vitamin, along with vitamins A, D, and E, meaning that it can be stored in fat cells instead of being excreted by the kidneys. Vitamin K is also synthesized by bacteria in our gastrointestinal tract as a byproduct of their metabolism, which further contributes to overall intake.

Key Takeaways

Vitamin K plays a crucial role in blood coagulation, which is the process by which the body forms clots to stop bleeding. Vitamin K acts as a cofactor for a group of proteins known as the vitamin K-dependent clotting factors (II, VII, IX, and X ), which are involved in the activation of blood-clotting proteins. To be useful, vitamin K undergoes a series of oxidation and reduction reactions called the vitamin K cycle.

Vitamin K deficiency can result in impaired blood clotting, leading to spontaneous bleeding or excessive bleeding from cuts or injuries. Newborn infants are at particular risk because they have limited stores of vitamin K, and are often not able to produce enough of the vitamin on their own. This is why they are typically given a single injection of vitamin K shortly after birth.

Sources

  1. "Medical Physiology" Elsevier (2016)
  2. "Physiology" Elsevier (2017)
  3. "Human Anatomy & Physiology" Pearson (2018)
  4. "Principles of Anatomy and Physiology" Wiley (2014)
  5. "The role of vitamins in hemostasis" Thromb Diath Haemorrh (1975)
  6. "Vitamin K--dependent clotting factors" Semin Thromb Hemost (1977)