Vitamin K Sources and Functions

Vitamin K Sources and Functions

All of the vitamins work together to keep you healthy and feeling good. Here is a summary of the role of Vitamin K, a fat-soluble vitamin, in your good health.

What it does Necessary for blood clotting and bone health
Daily needs (AI#) [Infants*: 2-2.5 µg][Children†: 30-75 µg][Men: 120 µg]
[Women: 90 µg] [Pregnant: 90µg] [Lactating: 90 µg IU]
Not enough Uncontrolled bleeding, bruising, nosebleeds
Too Much No known toxic effects
Foods Dark leafy green vegetables, vegetables in the cabbage family, milk, liver, olive oil, blackberries

*The lower value is for infants up to 6 mos.,higher value is for infants up to a year old.
† The first value is for children 1-3 with the amount increasing until age 18.
# Vitamin K needs are based in Adequate Intake “AI”, the amount the average healthy person consumes. There is not enough scientific evidence to establish an RDA.

Produced in Digestive Tract

Vitamin K can be made by the friendly bacteria in your digestive tract. This means that you don’t need to get as much from your diet.

Deficiency rare

Vitamin K deficiency is not common except in those groups who have diseases that affect fat absorption, or in those taking antibiotics that can destroy the friendly, Vitamin K- producing bacteria in the digestive tract. Some health experts recommend that you eat yogurt or take probiotics to replace the friendly bacteria.


Interesting Fact about Vitamin K Sources and Functions: Although they pick up some beneficial bacteria on their way through the birth canal,  the digestive tracts of newborns are pretty clean. this means they may not have even the friendly bacteria that make Vitamin K. As a result, many newborns are given a Vitamin K injection to protect them from the potential of uncontrolled bleeding.

This practice has come under fire recently as being a cause of childhood cancer, but so far the research that has been done does not indicate that there is any correlation between the Vitamin K shots and cancer in children.

As usual, it is a matter of making a decision between the benefits and possible risks.


In general, people who live in developed countries like the United States get enough Vitamin K. However, those suffering from eating disorders or living in poverty may not be eating enough food to get sufficient Vitamin K in their diet.

--Caveat: Hydrogenated vegetable oils may reduce the absorption of Vitamin K. Since hydrogenation also produces those bad actors called trans-fats, it is wise to avoid them anyway.

It's good for your bones, too!

Although most people associate Vitamin K with blood clotting, it has been more recently found to be important in the making of the proteins in bones. Studies are ongoing as to the relation of Vitamin K to osteoporosis in the elderly and to atherosclerosis.

The dark green leafies win again!

Some good food sources of Vitamin K are spinach, broccoli, kale, Swiss chard, cabbage, romaine and parsley.

Other sources of Vitamin K are liver, milk, olive oil, canola oil, and soybean oil.

What about supplements?

It is always best to get your vitamins from fresh, whole foods whenever possible. If you decide to take a supplement and you also take prescription medication, you should discuss with your doctor and pharmacist the possible interactions with Vitamin K.


Interesting Fact about Vitamin K Sources and Functions: Some health care providers are recommending Vitamin K as beneficial for treatment and prevention of the virus that has been sweeping through the world. Stay tuned for more studies.


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