Vitamin K: A Powerhouse Nutrient
Vitamin K: A Powerhouse Nutrient
Written By Nicole Crane, B.S., NTP
Imagine stopping to smell a fragrant red rose and pricking your finger on a hidden thorn. Just a minor puncture, but your body goes to work immediately to stop the bleeding and quickly seal the wound. One of the major nutrients at work is Vitamin K, discovered in the 1930s and named after the German word Koagulation. Vitamin K’s most essential role is in coagulation, or blood clotting, due to its function in the creation and activation of clotting factors. These factors work together to form blood clots and scabs, an essential supportive step in the healing process. Clotting is just one of the many versatile roles of Vitamin K. This superhero nutrient is also critical for a healthy heart, strong bones and normal calcium absorption. Further, Vitamin K is a great asset in optimal blood sugar balance and healthy cell growth. With widespread action from its role in protein activation, Vitamin K has long been underestimated.
Forms and Foods
Vitamin K is the name for several related compounds which share a basic chemical structure. Vitamin K1, known as phylloquinone, is the inactive form. It is sourced from vegetables, especially dark leafy greens like kale, spinach and Swiss chard. Active Vitamin K2 comes in several forms called menaquinones. MK7 and MK4 have been identified as forms of K2 with the most activity. MK4 is found in pastured dairy and butter, organic eggs and naturally raised meats. Lamb and liver are especially good sources of MK4. MK7 is made by bacteria, making fermented foods like cheese, kim chi, pickles, sauerkraut and natto, a fermented soybean paste, among the best food sources. MK-9 is another active form of K2, made by the proprioni bacteria used to ferment cheeses with air holes, like Swiss cheese.
Vitamin K is a fat soluble nutrient, meaning it requires dietary fats, pancreatic digestive juices and bile produced by the liver for optimal absorption. Vitamin K rich foods should be consumed with a meal or other source of fat, like cooking with butter or using an olive oil based salad dressing. Supplements should be taken with a meal rich in healthy fats, or at least a handful of raw nuts or seeds. Consuming one serving of K2 stays active in body for several days, where K1 is absorbed and used in several hours. K1 is recycled and used again, while K2 is not reused and ideally should be consumed daily. The K2 forms are significantly more absorbable than the plant-based K1 forms, especially when supplementing.
Vitamin K has direct influence over at least seven clotting factors, made of specialized proteins. These are essential to stop bleeding by forming a blood clot. This is done using a process called carboxylation, or adding a compound made of one carbon, one hydrogen and two oxygen molecules (COOH). Carboxylation makes a particular protein, glutamic acid, in the clotting factors sticky. The stickiness helps the clotting factors adhere to one another and build what becomes a blood clot. Each protein-based clotting factor adds a particular ingredient to construct the layers of a clot or scab, like building a brick wall. Other Vitamin K dependent proteins have anti-coagulation properties. This keeps the clotting cascade in balance and allows for control and regulation over this life-saving mechanism. The ability to clot properly is a necessary function throughout the body, not just on the skin’s surface. Any internal injury also requires the clotting cascade to swoop in and repair the damage. Without enough Vitamin K, the risk of uncontrolled bleeding, or hemorrhage, becomes significantly greater. Yet, affecting the proteins that generate blood clotting is just one of many functions of Vitamin K.
IMPORTANT NOTE: Due to the effect of Vitamin K and K-rich foods on those taking prescription blood thinners like Coumadin (Warfarin), supplemental K should be avoided and individuals should speak to their health practitioner about the proper intake of Vitamin K foods.
Building strong, healthy bones and teeth involves many vitamins, minerals and proteins beyond calcium. Despite their rigidity, bones are quite alive, in a constant state of being built up and broken down. These two processes are regulated by cells called osteoblasts, which build new bone, and osteoclasts, which break down bone tissue. Osteocalcin, a protein made by the bone building osteoblast cells, is dependent on Vitamin K for proper functioning. Osteocalcin’s ability to bind minerals is depends on carboxylation processes similar to those involved in blood clotting. Carboxylation is what helps make minerals sticky so they can bind together, making bones dense and strong. Bones are made by laying down a base of collagen and other proteins, which are then filled in with mineral crystals like calcium, magnesium and phosphorus. This action is directly driven by the presence of enough Vitamin K. Osteocalcin, which cannot become sticky due to lack of Vitamin K, may be a major factor in bone breaks and fractures.
Another protein called matrix GLA protein (MGP) is also Vitamin K dependent. It has been found in several different structural tissues, like bone, cartilage and other soft tissues including blood vessels. The calcium-binding protein can also be found in the heart, lungs and kidneys. MGP has several roles in the normal development and growth of bone tissue. Proper regulation of MPG will ensure that calcium and other minerals end up in the bones and teeth. With optimal mineral absorption, bones and teeth grow stronger and denser. MGP also protects cartilage and soft tissue from becoming calcified, or hardened, because of mineral deposits. Vitamin K’s influence over this protein may ward off kidney stones and protect against calcium deposits in the arteries and other soft tissues. In their active forms, Vitamins D3 and K2 work together to build strong bones. Vitamin D regulates the osteoblast cells which make osteocalcin, a Vitamin K dependent protein. MGP production is also increased by healthy levels of Vitamin D. The synergistic relationship between Vitamin D and Vitamin K is a powerful combination for building and maintaining healthy bones.
Blood Sugar Balance
Osteocalcin does more than just build bone tissue. This protein is also a hormone, and affects the insulin-secreting beta cells in the pancreas. Osteocalcin entices the release of more insulin, resulting in a number of other effects. Insulin itself is a complex hormone which directs our bodies how to use calories, regulates blood sugar, influences energy production and many other roles. Osteocalcin also sends instructions to the fat cells to release the hormone adiponectin, a key factor in insulin sensitivity. As Vitamin K controls proteins which regulate osteocalcin, a deficiency of this nutrient can affect insulin production. Vitamin K’s effect on the way the body makes and uses insulin helps to keep blood sugar within normal ranges. Healthy blood sugar levels support overall wellness, including healthy body weight, optimal inflammatory response, proper nerve function, and normal stress responses.
Cellular Growth & Immunity
Another protein which requires Vitamin K is called Growth Arrest-Specific 6, (GAS6) and is similar to one of the clotting factors. GAS6, can be found through the body, in the heart, kidneys, stomach, cartilage and lungs. This protein has a direct influence on regulating the growth of cells. It enhances cell signaling and communication as well as cell adhesion and duplication. This protein also protects healthy cells from programmed cell death. The capacity to bind to cell membranes allows GAS6 to aid in the removal of cells which need to undergo apoptosis. Apoptosis is a critical function the body uses to induce death in cells which are damaged or unwanted. GAS6 binds to dead cells and brings them to phagocytes, or special cells which ‘eat’ dead cells after apoptosis. The protein also helps remove the unwanted cell without damaging the surrounding tissue, a significant factor in preventing inflammation and pain. The process of removing undesirable cells and generating new, healthy cells is vital for maintaining healthy tissues and balanced immune responses. Vitamin K activates the proteins that perform these tasks, keeping the immune system running optimally and helping the body run efficiently at the cellular level.
Nervous System Function
GAS6 seems to have roles in regulating the development of the nervous system. Both Vitamin K1 and K2 function in preventing free radical damage to cells, particularly nerve cells. Free radicals cause oxidative damage, which breaks down cell components, speeds aging and turns on inflammation. Vitamin K is also required to make fats called sphingolipids, which are vital for the brain and nervous system. These fats help form the myelin sheath which coats each nerve cell and helps to optimize cell-to-cell communication. The myelin sheath is like giving microphones to a group of children playing the game telephone. Optimal nervous system communication has wide-spread positive impact throughout the body. Healthy intake of Vitamin K seems to control GAS6 functions that influence how the nervous system ages over a lifetime. This can impact memory, thinking, focus, balance and overall brain health, especially among older adults.
The GAS6 protein is quite protective of the heart and vascular system. This K dependant protein helps to regulate inflammation and promotes the growth of new blood vessels. Vitamin K’s ability to activate proteins also helps to prevent plaque formation and calcification of the arteries. K’s influence over mineral binding ensures that calcium is not deposited into soft tissues, which are easily damaged by mineralization. Healthy levels of Vitamin K itself can significantly lower markers of inflammatory activity, fostering heart health and reducing inflammation throughout the body.
The same MGP protein that supports strong bones also contributes to vascular health through the same calcium regulating mechanism. The body uses MGP to regulate calcium absorption from foods we eat, directing it into bones. MGP also actively blocks calcium crystals from forming inside blood vessels. This process is as critical for strong bones as it is for healthy blood pressure. Consumption of K2 supports activation of proteins which can prevent arterial hardening. When blood vessels are flexible, the body has an easier time maintaining optimal blood pressure levels. MGP directed calcium regulation also supports the heart by making calcium available for a healthy heart rhythm. Every time the heart muscle contracts, calcium is required. Further, the role of Vitamin K in blood clotting has influence over the viscosity, or thickness, of blood. Normal blood viscosity is essential for healthy circulation and a well-functioning heart muscle. By activating these important proteins, Vitamin K directly supports several different aspects of heart and vascular health.
Dosing and Enhancing Intake
Vitamin K’s influence over proteins accounts for its function in so many different body tissues. With so few Americans consuming enough K1 rich leafy green vegetables, this nutrient is attracting more attention for its diverse health promoting actions. Vitamin K’s widespread action is based on activating several important proteins through the process of carboxylation. This essential mechanism requires a minimum of 200 micrograms (mcgs) before any activation occurs. While 200 mcgs is the bare minimum to gain health benefits, therapeutic doses are closer to 5 mg, or 5,000 mcg. Higher dietary intake or supplementation in this range has great benefits in bone remineralization and clearing of arterial plaque. Both K1 and K2 are available as supplements, though active K2 is the significantly better choice, with greater absorption and benefits, with longer lasting effects.
Vitamin K is fairly resilient to cooking, processing and storing, although there is some concern over nutrient loss during freezing. Fat soluble Vitamin K seems to become more concentrated in cooking, as water evaporates from food. Limited fat intake prevents proper absorption, while pairing K rich foods with healthy fats enhances intake significantly. Excessive intake of Vitamin E (over 1500 IUs daily) or over 10,000 IUs of the retinol form of Vitamin A can alter the clotting effects of Vitamin K.
There are few nutrients which support as many different body systems as Vitamin K does. This single, spectacular nutrient supports the heart, vessels, brain, nerves, bones, weight control, blood sugar and energy, reduced inflammation and rapid healing. Only Vitamin D3 may be more versatile, and the two work closely together to support the essential functions of the other. As more is discovered about the whole body benefits of this powerhouse nutrient, hopefully it will gain the attention and recognition it deserves. Vitamin K gives us a new reason to eat our veggies and fermented foods.