How Vitamin K Works


Vitamin K: It's found in certain vegetables, in beef and chicken livers, even in ourselves. Yes, we have the ability to make vitamin K -- and we do, creating about 1/3 of what we need -- via bacteria in our intestines. In this article, we'll discuss what vitamin K is, why it is important, where you can find it and more. Here is a brief overview of what we'll cover.
  • What Is Vitamin K?

    First recognized by a Danish scientist in 1929, Vitamin K is a huge help to the body. It not only assists blood with clotting, Vitamin K also helps build bone strength by helping to make a protein called osteocalcin that binds calcium, which indicates that vitamin K may play a role in preventing osteoporosis. Learn more about this important vitamin on this page.
  • Foods That Contain Vitamin K

    Some vitamin K is produced naturally in the body with the help of bacteria; however, it's our responsibility to include vitamin K in our diet, as well. A number of foods contain vitamin K, including green, leafy vegetables such as spinach, broccoli and lettuce, and beef, chicken and pork liver. Green tea is a wonderful source of vitamin K. In this section, learn which foods are the best vitamin K sources.
  • Vitamin K Deficiency

    Despite eating a healthy diet, sometimes vitamin K deficiency can occur. Liver or gall bladder disease, or any disease of the intestinal tract that interferes with absorption of fats, can cause a deficiency.  So can long-term antibiotic high-blood cholesterol medication. Newborn babies are born without the bacteria needed to create vitamin K. Find out what factors can contribute to vitamin K deficiency.
  • Vitamin K Supplements

    As with newborn babies, or certain liver, gall bladder or intestinal tract disease patients, vitamin K supplementation is sometimes needed. But how much, and who needs it? In this section, we take a look at why babies receive vitamin K right after birth and who else will need to be on the look out for vitamin K deficiency. Too much vitamin K is toxic, so being informed is key.

Other vitamins can help maintain and regulate health. Some vitamins you might want to learn more about include:
  • Vitamin A is the vitamin found in carrots that improves eyesight. Learn more about this key vitamin in How Vitamin A Works.
  • Vitamin B3, also called niacin, assists other substances in the conversion of protein, carbohydrate and fat into energy. Learn more in How Vitamin B3 Works.
  • How Vitamin C Works will show you how this vitamin can strengthen your immune system.
  • Discovered only about 60 years ago, Biotin assists in several metabolic reactions. Learn more about it in How Biotin Works.
  • Vitamin B12 has a a chemical structure much more complex than that of any other vitamin. Learn about this vitamin How Vitamin B12 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • .

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

What Is Vitamin K?

Vitamin K plays a very important function in the body -- helping blood to clot and assisting calcium retention, which helps prevent osteoporosis. Yet its value as a vitamin wasn't always known.

The importance of a dietary factor in blood clotting was first recognized by a Danish scientist. In 1929, he reported that chicks fed diets lacking a particular dietary factor hemorrhaged. Their blood was slow to form the clots needed to control bleeding. The missing factor was vitamin K.

People who have trouble absorbing fat and, therefore, vitamin K, along with those on long-term antibiotic therapy, may need to take vitamin K supplements. When blood clotting time is slow, vitamin K is given before surgery to avoid excessive bleeding.

Vitamin K helps blood clot.
©2007 Publications International, Ltd.
Vitamin K helps blood clot and helps bones to hold on to calcium.

Because of vitamin K's ability to help produce osteocalcin, it helps the bones to hold onto calcium, possibly preventing osteoporosis.

Occasionally women who have heavy menstrual periods get relief from supplementing their diet with vitamin K. Even if their blood levels of this vitamin are in the normal range, supplements reduce the excessive bleeding in some women.

Some small studies have also shown a benefit for pregnant women. Small supplemental doses, about 50 mg, often reduces the nausea associated with the first trimester of pregnancy.

Vitamin K can be found in several foods. We'll discuss which foods are best and how much you need in the next section.

Vitamin K is a huge help to they body via blood clotting, but there are other vitamins you may want to learn about as well.
  • Vitamin A is the vitamin found in carrots that improves eyesight. Learn more about this key vitamin in How Vitamin A Works.
  • Vitamin B3, also called niacin, assists other substances in the conversion of protein, carbohydrate and fat into energy. Learn more in How Vitamin B3 Works.
  • How Vitamin C Works will show you how this vitamin can strengthen your immune system.Discovered only about 60 years ago, Biotin assists in several metabolic reactions. Learn more about it in How Biotin Works.
  • Vitamin B12 has a a chemical structure much more complex than that of any other vitamin. Learn about this vitamin How Vitamin B12 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

Foods That Contain Vitamin K

Vitamin K should be an important dietary elements, but where do you find vitamin K? It can be found in a number of foods, including some types of produce and beverages.

The best food sources of vitamin K are green leafy vegetables such as cabbage, turnip greens, broccoli, lettuce, and spinach. Green tea is another good source with one cup giving you your daily requirement of this nutrient. 

Broccoli is a great source of vitamin K.
©2007 Publications International, Ltd.
Green vegetables such as broccoli are great sources of vitamin K

Beef liver is another good source; chicken liver, pork liver, milk, and eggs contain smaller amounts of the vitamin. Liver, however, may also contain environmental toxins. Other sources, such as green tea, are better choices.

Not all of the vitamin K we get comes from the foods we eat. About one-third of our vitamin K comes from the bacteria living in our digestive tracts, which produce this vitamin as a by-product of their own metabolism. It used to be thought that intestinal bacteria produced about one-half of our vitamin K needs, but current findings indicate this was an overestimation.

Here is a chart you can use to find foods rich in vitamin K:

Food
  Quantity  Vitamin K (mg)
Turnip greens
   2/3 cup        650
Lettuce    1/4 head
      129
Cabbage    2/3 cup
      125
Liver, beef
   3 ounces        110
Broccoli    1/2 cup        100
Spinach    1/2 cup
       80
Asparagus    2/3 cup
       57
Liver, pork
   3 ounces
       30
Peas    2/3 cup
       19
Ham    3 ounces
       18

Dietary Requirements
For a long time, we didn't know enough about vitamin K to establish requirements. The first recommendation for the vitamin wasn't established until the 1989 edition of the RDAs.

The requirement varies by age; for men, it ranges from 75 to 120 mg as age increases from 11 to over 50 years. For women, the range is from 75 to 90 mg. A typical well-balanced diet in the United States supplies 300 to 500 mg of vitamin K -- more than enough to meet average dietary needs.

However, not every person meets the basic vitamin K requirements. In the next section, we'll discuss how even some healthy eaters with the best of intentions can become vitamin K deficient.

In addition to vitamin K, some other vitamins you might want to learn more about include:
  • Vitamin A is the vitamin found in carrots that improves eyesight. Learn more about this key vitamin in How Vitamin A Works.
  • Vitamin B3, also called niacin, assists other substances in the conversion of protein, carbohydrate and fat into energy. Learn more in How Vitamin B3 Works.
  • How Vitamin C Works will show you how this vitamin can strengthen your immune system.
  • Discovered only about 60 years ago, Biotin assists in several metabolic reactions. Learn more about it in How Biotin Works.
  • Vitamin B12 has a a chemical structure much more complex than that of any other vitamin. Learn about this vitamin How Vitamin B12 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • .
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

Vitamin K Deficiency

We've learned why vitamin K is important; but sometimes, no matter how many leafy green vegetables you eat, you can still become vitamin K deficient. Unfortunately, a vitamin K deficiency can sometimes be caused by other diseases, such as liver or gall bladder disease, or any disease of the intestinal tract that interferes with absorption of fats.

Long-term use of antibiotics kills off the bacteria in the intestines that manufacture the vitamin. This can lead to a deficiency, especially if coupled with a diet that doesn't provide enough vitamin K.
Use of mineral oil or medications such as cholestyramine to lower blood cholesterol can interfere with vitamin K absorption. With extended use, this can lead to a deficiency.

Newborn babies, especially those born prematurely, are born with little vitamin K. For the first couple of days after birth, the baby's intestinal tract has no bacteria to make the vitamin. Moreover, the primary source of a baby's nutrition -- milk -- is not a good source of vitamin K. Because the lack of vitamin K could lead to bleeding problems, babies are given a vitamin K supplement within the first couple of days after birth.

Newborn babies receive vitamin K.
©2007 Publications International, Ltd.
Newborns are given vitamin K after birth, when their intestinal
tract has no bacteria to create the vitamin.

Rest assured there are ways to increase your vitamin K intake if you aren't getting enough in your diet. In the next section, we'll discuss vitamin K supplements.

Vitamin K deficiencies can be debiliating, but not getting enough of the following vitamins can also cause issues:
  • Vitamin A is the vitamin found in carrots that improves eyesight. Learn more about this key vitamin in How Vitamin A Works.
  • Vitamin B3, also called niacin, assists other substances in the conversion of protein, carbohydrate and fat into energy. Learn more in How Vitamin B3 Works.
  • How Vitamin C Works will show you how this vitamin can strengthen your immune system.
  • Discovered only about 60 years ago, Biotin assists in several metabolic reactions. Learn more about it in How Biotin Works.
  • Vitamin B12 has a a chemical structure much more complex than that of any other vitamin. Learn about this vitamin How Vitamin B12 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
  • Find the best prices on vitamin K supplements.
This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

Vitamin K Supplements

Vitamin K can be found in certain foods, but how do you know how much you need? With vitamin K, a little goes a long way. Supplements of 150 to 500 mg of plant-derived vitamin K are plenty.

It's best to get vitamin K from green leafy vegetables if possible. However, sometimes more vitamin K is needed and in that cases, supplements are given.
Most babies in the U.S. get an injection of vitamin K at birth to avoid hemorrhagic disease, which is characterized by uncontrolled bleeding. Babies depend on this long-lasting injection until vitamin K-producing bacteria become established in their digestive tracts.

Vitamin K is also a concern for persons with heart disease and other disorders than affect clotting. Anticoagulants (blood thinners, such as dicumarol or warfarin) are used in the treatment of
heart disease and other diseases that cause the blood to clot too easily. Blood thinners interfere with the action of vitamin K and slow down the clotting process. People taking anticoagulants may inadvertently reduce the action of the drug by eating vitamin K-rich foods.

Vitamin K supplements are given to babies and heart disease patients.
©2007 Publications International, Ltd.
Vitamin K supplements are given to heart disease patients and patients
with other diseases that can affect clotting.

Vitamin K from food and bacteria is not toxic. However, the synthetic form of vitamin K, menadione, can be toxic. Large doses of this form break down red blood cells and can lead to a jaundice condition and possibly even brain damage when given to infants or pregnant women. If you wanted to find the best deals on vitamin K supplements, click here.

The body needs vitamin K to help with its blood clotting. Luckily, vitamin K in in abundance -- it comes from the foods we eat, including produce such as broccoli and lettuce, and about one-third of our vitamin K comes from the bacteria living in our digestive tracts, which produce this vitamin as a by-product of their own metabolism. In some cases, such as for newborn babies, additional vitamin K supplements are required. However, no matter what the intake method is, vitamin K is a crucial part of the body's blood regulation and assists with bone strength.

Vitamin K deficiencies can be debilitating, but not getting enough of the following vitamins can also cause issues:
  • Vitamin A is the vitamin found in carrots that improves eyesight. Learn more about this key vitamin in How Vitamin A Works.
  • Vitamin B3, also called niacin, assists other substances in the conversion of protein, carbohydrate and fat into energy. Learn more in How Vitamin B3 Works.
  • How Vitamin C Works will show you how this vitamin can strengthen your immune system.
  • Discovered only about 60 years ago, Biotin assists in several metabolic reactions. Learn more about it in How Biotin Works.
  • Vitamin B12 has a a chemical structure much more complex than that of any other vitamin. Learn about this vitamin How Vitamin B12 Works.
  • To learn about the many vitamins in our diet, how much you should be eating, and where to find them, go to our general Vitamins page.
ABOUT THE AUTHOR

Jennifer Brett, N.D. is director of the Acupuncture Institute for the University of Bridgeport, where she also serves on the faculty for the College of Naturopathic Medicine. A recognized leader in her field with an extensive background in treating a wide variety of disorders utilizing nutritional and botanical remedies, Dr. Brett has appeared on WABC TV (NYC) and on Good Morning America to discuss utilizing herbs for health.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.