Vitamin K (VK) is a group of substances with chlorophyll quinone bioactivity, primarily found in VK1 and VK2 forms. Initially recognized for its role in blood coagulation, VK has shown potential in preventing and treating various diseases, including infections, inflammation, and autoimmune disorders. This review explores VK's mechanisms of action and its potential therapeutic effects on infections such as asthma and COVID-19, inflammation in conditions like type 2 diabetes, Alzheimer's disease, and cancer, and autoimmune disorders such as inflammatory bowel disease and multiple sclerosis. VK-dependent proteins (VKDPs) play a crucial role in its anti-inflammatory and immunomodulatory effects. VK also contributes to preventing aging, combating neurological abnormalities, and treating diseases like cancer and diabetes. Current research highlights VK's potential as a therapeutic tool for clinical applications in infections, inflammation, and autoimmune diseases, although further studies are needed to fully understand its mechanisms and optimize its use. VK's role in regulating immune responses, antioxidant activity, intestinal microbiota, and bone health is increasingly recognized. VK2, in particular, has shown promise in improving bone health, reducing inflammation, and enhancing mitochondrial function. VK also plays a role in cancer treatment by inhibiting tumor growth and cell cycle progression. Additionally, VK is involved in the prevention and treatment of atherosclerosis by reducing vascular calcification and improving cardiovascular health. VK's potential in autoimmune diseases such as rheumatoid arthritis and multiple sclerosis is also being explored. Overall, VK's diverse biological functions and therapeutic potential make it a promising candidate for further research and clinical application in various diseases.Vitamin K (VK) is a group of substances with chlorophyll quinone bioactivity, primarily found in VK1 and VK2 forms. Initially recognized for its role in blood coagulation, VK has shown potential in preventing and treating various diseases, including infections, inflammation, and autoimmune disorders. This review explores VK's mechanisms of action and its potential therapeutic effects on infections such as asthma and COVID-19, inflammation in conditions like type 2 diabetes, Alzheimer's disease, and cancer, and autoimmune disorders such as inflammatory bowel disease and multiple sclerosis. VK-dependent proteins (VKDPs) play a crucial role in its anti-inflammatory and immunomodulatory effects. VK also contributes to preventing aging, combating neurological abnormalities, and treating diseases like cancer and diabetes. Current research highlights VK's potential as a therapeutic tool for clinical applications in infections, inflammation, and autoimmune diseases, although further studies are needed to fully understand its mechanisms and optimize its use. VK's role in regulating immune responses, antioxidant activity, intestinal microbiota, and bone health is increasingly recognized. VK2, in particular, has shown promise in improving bone health, reducing inflammation, and enhancing mitochondrial function. VK also plays a role in cancer treatment by inhibiting tumor growth and cell cycle progression. Additionally, VK is involved in the prevention and treatment of atherosclerosis by reducing vascular calcification and improving cardiovascular health. VK's potential in autoimmune diseases such as rheumatoid arthritis and multiple sclerosis is also being explored. Overall, VK's diverse biological functions and therapeutic potential make it a promising candidate for further research and clinical application in various diseases.