Which one of the following vitamins is essential for the coagulation of blood ?

Vitamin K is essential for the coagulation of blood because it acts as a vital co-factor for the synthesis of several clotting proteins in the liver [t1][t2]. Specifically, it is required for the post-translational modification (gamma-carboxylation) of coagulation factors II (prothrombin), VII, IX, and X [t6][t7]. This process allows these factors to bind calcium ions, which is a critical step in the coagulation cascade that prevents excessive bleeding [t1][t10]. A deficiency in Vitamin K leads to impaired coagulation, resulting in prolonged clotting time and increased susceptibility to bruising or hemorrhaging [t3][t4]. While other vitamins like B12 are important for red blood cell formation, they do not play a direct role in the clotting mechanism [c1]. Therefore, Vitamin K is the primary nutrient responsible for maintaining effective hemostasis [t7].

Sources

1. [1] https://www.ncbi.nlm.nih.gov/books/NBK551578/
2. [2] https://www.sciencedirect.com/topics/food-science/vitamin-k
3. [3] https://www.healthdirect.gov.au/vitamin-k-deficiency
4. [4] Science-Class VII . NCERT(Revised ed 2025) > Chapter 6: Adolescence: A Stage of Growth and Change > Science and Society > p. 80