Transcription
Now we have gone through the entire hemoasis process. But before moving on to the processes that occur after hemostasis, I want to emphasize the role of another substance involved in blood clotting, vitamin K.
It turns out that vitamin K is very important for the production of certain factors. In any case, the factors of secondary hemostasis, all those involved in the cascade are produced in the liver. Vitamin K is specifically important for the production of factors 2, 7, 9, and 10. Therefore, adequate intake of this vitamin, its metabolism in the body and its proper utilization are essential for hemostasis to function effectively.
First, where can we find vitamin K? The richest sources of vitamin K are various leafy vegetables such as cabbage, spinach, parsley, broccoli, brussel sprouts, and also asparagus. In short, if it's green, has leaves, and is similar or related to cabbage, it is most likely a good source of vitamin K. If leafy greens are not appealing, then some tastier sources include grapes, kiwi, eggs, and chicken. Although in much smaller amounts compared to leafy greens, vitamin K is considered a fats soluble vitamin. Besides vitamin E, D and A. Because vitamin K is fat soluble, it can be stored in fat cells and is not excreted through the liver.
In addition to dietary intake, vitamin K is also produced by bacteria, the natural microbiota in the intestinal tract alongside other vitamins such as biotin. However, two important points should be considered. First, the natural microbiota likely does not produce sufficient amounts of vitamin K. And second, these bacteria need nutrients to produce it. In other words, adequate intake of dietary fiber is necessary to support these bacteria so they can actually produce vitamin K and of course other vitamins.
Finally, for vitamin K to function in the body, it must participate in a series of biochemical reactions known as the vitamin K cycle. I will not go into detail about these reactions as the coagulation cascade is already complex enough. However, it is important to know that this vitamin K cycle can be affected or inhibited by certain medications such as warpherin. Warerin is well known as drug that inhibits hemostasis because as we have established vitamin K is necessary for the production of several coagulation factors. Therefore, if vitamin K is lacking or its cycle is inhibited, hemostasis cannot proceed effectively. In medicine, this effect is sometimes intentionally used.
Now, a brief recap of secondary hemoasis, focusing on how vitamin K and its inhibition affect the coagulation cascade. First, one of the factors whose production depends on vitamin K is factor 7. The extrinsic pathway begins with factor 7 which means that without it the extrinsic pathway cannot start at all. Another factor dependent on vitamin K is factor 9. This factor is part of the intrinsic pathway and without factor 9 the intrinsic pathway cannot proceed to its end point. Therefore the intrinsic pathway cannot function properly. Factor 10 which marks the convergence into the common pathway also requires vitamin K for its production. Without factor 10, the common pathway cannot proceed. And finally factor 2 should be mentioned. In its inactive form, it's protrumbin and in its active form, it's trombin. As you have already seen, trombin performs a very large number of functions within the common pathway. This means that if vitamin K is lacking or its cycle is inhibited, all of these processes are impaired. Therefore, vitamin K in the end is a crucial component of secondary hemostasis.