Vitamin K

Several proteins involved in blood clotting depend on vitamin K to get their job done. Blood clotting is often mentioned as a bad thing, when it is excessive. But like a lot of things in our bodies, it is all about balance.

There are actually vitamin K-dependent proteins required for proper bone health. This fat-soluble vitamin has to be present for an enzyme called gamma-glutamyl carboxylase to make the protein osteocalcin work, through a process called carboxylation, which is required for bone growth.
May help to prevent fractures due to osteopenia and osteoporosis.

Vitamin K-dependent proteins (VKDP) that require the intake of vitamin K to function properly don’t just affect bone modeling. The VKDPs not associated with bone growth or blood clotting are involved with the metabolism of sphingolipids, a class of lipids commonly found in brain cell membranes that are involved with cellular events. Changes in sphingolipid metabolism have been linked with not only age related cognitive decline but also neurodegenerative conditions like Alzheimers.
Higher vitamin K levels, specifically phylloquinone (K1), are associated with improved verbal episodic memory though no difference was observed with non-verbal episodic memory.

The intake of VK-rich diets or VK supplements could prevent age-related diseases and/or support the effectiveness of medical treatments. Vitamin K can carboxylate osteocalcin (a protein capable of transporting and fixing calcium in bone), activate matrix Gla protein (an inhibitor of vascular calcification and cardiovascular events) and carboxylate Gas6 protein (involved in brain physiology and a cognitive decline and neurodegenerative disease inhibitor).
By improving insulin sensitivity, vitamin K lowers diabetes risk. It also exerts antiproliferative, proapoptotic, autophagic effects and has been associated with a reduced risk of cancer. Recent research shows that protein S, another vitamin K-dependent protein, can prevent the cytokine storm observed in COVID-19 cases.

Getting an adequate intake of vitamin K may also be essential to your heart health because it may be able to help prevent hypertension (abnormally high blood pressure) and lower your risk of cardiovascular disease (more on that in a second). Low vitamin D and K status have been linked to hypertension with increases in both systolic and diastolic blood pressure.
Like Vitamin D, vitamin K interacts closely with calcium in your body, in this case, helping to regulate the levels of this mineral in your blood. Vascular calcification—a process in which minerals like calcium are deposited in blood vessels, blocking blood flow over time—is common as we age. But getting the proper amount of vitamin K may help prevent mineralization, staving off this process, and keeping blood pressure lower

Your risk of a cardiovascular event is closely associated with the calcification of your blood vessels. In fact, one meta-analysis that looked at 30 studies found a 300–400 percent increase in your risk of cardiovascular events with the presence of calcification on any arterial wall. But higher blood levels of the K1 form of vitamin K are associated with a lower risk of heart disease.

Additionally, a recent study suggests that a combination of Vitamin D and K1 can help reduce the risks of a first stroke in already hypertensive people.