Vitamin K Facts: Everything You Need to Know

In many women's magazines nowadays, vitamin K has become an often-mentioned key player not only for its anti-aging properties, but also for its role in reducing sleep-deprived persons of those pesky dark circles under the eyes. However, this vitamin does so much more internally in addition to its beauty benefits; this nutrient also stops excessive bleeding and strengthen bones. Here is everything you will need to know about vitamin K.

What Does Vitamin K Do?

Vitamin K's name originated from the German word, "koagulation" ("coagulation" in English), which refers to the process of blood clot formation. It is a vital nutrient for helping staunch an open wound to help the body prevent excess loss of blood. Without vitamin K, small cuts on an arm can prove to be lethal if the blood flow cannot be stopped.

Proteins in vitamin K, which are found in bones, work closely with calcium to help and promote bone mineralization. Although another nutrient, vitamin D, is the main generator of bone-forming cells, vitamin K is crucial in binding these cells together and mineralizing the bond. Not only does it strengthen the bones, but it also helps prevent bone fractures, as research has shown that women who had daily adequate intakes of vitamin K are less prone to osteoporosis later on in life.

Furthermore, this nutrient can also help prevent hardening of the cardiovascular system due to calcification, which is excessive calcium buildup either in soft tissues, arteries or heart valves. Thus, regular intake of the vitamin can help protect the heart and blood from diseases later in life, such as stroke and heart attack.

Research done on vitamin K also suggests its anti-inflammatory and anti-aging properties, as it serves as a cell-signaling nutrient that may help prolong cell life. In fact, many cosmetic scar treatment gels boasts vitamin K as a main ingredient due to its cell-strengthening properties. Since it protects the nervous system, liver, lungs, heart, cartilage, stomach and kidneys, vitamin K has also been mentioned as effective in preventative measures against many degenerative and fatal conditions, including Alzheimer's disease and liver cancer.

Food Sources of Vitamin K

Fortunately, vitamin K is readily available via a diverse selection of food sources. Specifically, the forms of vitamin K found in naturally occurring food sources are K1 and K2. The most prominent source of the nutrient is from dark-colored cruciferous vegetables, which includes but are not limited to, Brussels sprouts, Swiss chard, broccoli, kale and mustard greens. Other colorful vegetables, such as spinach, green beans, asparagus, romaine lettuce, tomatoes and peas, are also rich sources of the vitamin.

Several fermented foods contain high levels of vitamin K, since some strains of bacteria that facilitates the fermentation process is also vitamin K-generating. For example, the Propionibacterium genus of bacteria found in Swiss and Jarlsberg cheeses generates abundant amounts of vitamin K. Fermented soy products, such as soybean paste and Japanese natto, have a strain of B. subtilis that produces abundant amounts of vitamin K.

Vitamin K is also available as a dietary supplement. Usually, a daily multivitamin will have the sufficient recommended amount. The synthetic form of vitamin K is also known as K3, or menadione.

Side Effects

Since vitamin K is very important in blood coagulation, a deficiency in the nutrient will lead to problems with blood clotting. For someone who does not have a clotting factor, a small cut on the finger, or even a bruise, can prove to be fatal. The nutrient also plays a prominent role of regulating calcium, so too little vitamin K can lead to hardening of the arteries due to calcification, as well as weak bones. Deficiency in infants may lead to malformation of cartilage and bone structure.

Signs and symptoms of vitamin K deficiency in adults may include uncontrollable bleeding, excessive or proliferation of bruising, petechiae (characterized multitude of small red dots signifying hemorrhage sites under the skin) and cartilage calcification. Sometimes, vitamin K deficiency may signify absorption problems in the intestines, so be sure to see doctors if any of such symptoms are present so that he or she can correctly identify the source of deficiency. If left untreated, these symptoms can be life threatening, as too little vitamin K has also been linked to serious medical problems later in life.

So far, overdosing on vitamin K1 and K2, which are both from naturally occurring sources, has not been documented, so no tolerable upper level of the vitamin has been established by the Food and Nutrition Board. Although vitamin K generally is a fat-soluble substance and stays in the body longer, the only documented instances of vitamin K poisoning are from synthetic forms of the nutrient, known as menadione or vitamin K3. Excess menadione can lead to oxidative damage to cell membranes, liver toxicity, jaundice and anemia in infants.

Daily Dosage Recommendations

The U.S. Dietary Reference Intake (DRI) for vitamin K for healthy adult males is 120 mcg per day. For healthy adult women, the recommended intake is 90 mcg per day. For infants, 10 to 20 mcg per day would be enough, while children and adolescents need 15 to 100 mcg per day. However, if you are taking other medications or have a pre-existing medical condition, be sure to consult your physician for a professionally recommended amount of vitamin K intake, as the nutrient may interact negatively with one or both of such conditions.

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