Role of Vitamin K in coagulation

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Role of Vitamin K in coagulation

Final Review

Final Review

Cerebral circulation
Ischemic stroke
Atherosclerosis and arteriosclerosis: Pathology review
Platelet plug formation (primary hemostasis)
Coagulation (secondary hemostasis)
Role of Vitamin K in coagulation
Coagulation disorders: Pathology review
Anticoagulants: Warfarin
Anticoagulants: Heparin
Anticoagulants: Direct factor inhibitors
Frank-Starling relationship
Pressure-volume loops
Changes in pressure-volume loops
Heart failure
Heart failure: Clinical
Heart failure: Pathology review
Cardiac tamponade
Adrenergic antagonists: Beta blockers
Adrenergic antagonists: Alpha blockers
Calcium channel blockers
cGMP mediated smooth muscle vasodilators
Renin-angiotensin-aldosterone system
ACE inhibitors, ARBs and direct renin inhibitors
Osmotic diuretics
Loop diuretics
Potassium sparing diuretics
Thiazide and thiazide-like diuretics
Atrioventricular nodal reentrant tachycardia (AVNRT)
Pulmonary hypertension
Nephrotic syndromes: Pathology review
Nephritic syndromes: Pathology review
Nephritic and nephrotic syndromes: Clinical
Regulation of renal blood flow
Prerenal azotemia
Renal azotemia
Postrenal azotemia
Acute kidney injury: Clinical
Jaundice: Pathology review
Gallbladder disorders: Pathology review
Liver histology
Liver anatomy and physiology
Opioid agonists, mixed agonist-antagonists and partial agonists
Carbohydrates and sugars
Proteins
Gastroesophageal reflux disease (GERD): Clinical
The role of the kidney in acid-base balance
Nitrogen and urea cycle
Neuromuscular junction and motor unit
Neuromuscular blockers
Calcitonin
Parathyroid hormone
Growth hormone and somatostatin
Rheumatoid arthritis
Rheumatoid arthritis and osteoarthritis: Pathology review
Bone remodeling and repair
Osteoporosis
Osteomyelitis
Septic arthritis
Amino acid metabolism

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)