• Home
• About
• Contact NutriBody

What is Vitamin K?

Vitamin K is one of the primary substances responsible for proper blood clotting. Specifically, vitamin K is required for the liver to make factors that are necessary for blood to properly clot (coagulate), including factor II (prothrombin), factor VII (proconvertin), factor IX (thromboplastin component), and factor X (Stuart factor). Other clotting factors that depend on vitamin K are protein C, protein S, and protein Z. Deficiency of vitamin K or disturbances of liver function may lead to deficiencies of clotting factors and excess bleeding.

Only a small amount of Vitamin K is needed for good health and blood clotting functions and deficiency is rare.

Most people with a balanced diet are able to gain all of the vitamin K that they need from green, leafy vegetables and by the body’s natural ability to produce it. Generally, a deficiency is only seen in individuals with severely compromised digestive systems or those who have been on broad-spectrum antibiotics over a long term.

The majority of the Vitamin K that we get comes from plant sources. Some of the best sources of Vitamin K include cabbage, kale, swiss chard and most dark green leafy vegetables, soybeans and brussel spouts.

Mayo Clinic advises that if you are taking blood-thinning medications, such as Warfarin, or ASA on a regular basis, you may need to watch the amount of Vitamin K you are getting in your diet, as it may affect the drug’s function.

Since Vitamin K is made by the bacteria in the intestines, long-term use of antibiotics may affect the body’s ability to produce it.

Vitamin K is also helpful in strengthening bones, preventing osteoporosis, calcification of the arteries and certain cancers, notably prostate and liver cancer. This makes Vitamin K a particularly important vitamin for women and elderly people.

Vitamin K deficiency may be detected by excessive menstrual bleeding, bleeding gums, intestinal bleeding, bruising easily or nose bleeds. Bone problems such as weak bones, easily broken bones, bone loss and decreased bone density can also indicate a deficiency. Additionally, increased calcium deposits in soft tissue, especially in the arteries, can point toward a Vitamin K deficiency. If these symptoms are present, a simple blood test can determine whether proper Vitamin K levels are present in the body.

Wikipedia reports that while toxicity from taking too much of a synthetic form known as menadione is possible, overdose or toxicity from natural Vitamin K sources in the diet is highly unlikely and no cases have been reported. Such toxicity from the synthetic form can affect kidney and liver cells.

People with certain health conditions are more prone to a Vitamin K deficiency due to improper intestinal functioning. These include colitis, Crohn’s Disease, celiac disease, Irritable Bowel Disease, or any problems with liver, gallbladder or pancreas functions. These diseases impair the function of the digestive tract and can affect the body’s ability to produce the bacteria needed to produce Vitamin K or can inhibit its ability to absorb the Vitamin K that is produced.

Optimal levels of vitamin K in the body vary by age group and gender. The recommended levels as determined by the National Academy of Sciences are:

• Males and females, 0-6 months: 2 micrograms
• Males and females, 7-12 months: 2.5 micrograms
• Males and females, 1-3 years: 30 micrograms
• Males and females, 4-8 years: 55 micrograms
• Males and females, 9-13 years: 60 micrograms
• Males and females, 14-18 years: 75 micrograms
• Males, 19 years and older: 120 micrograms
• Females, 19 years and older: 90 micrograms
• Pregnant or lactating females, 18 years and younger: 75 micrograms
• Pregnant or lactating females, 19 years and older: 90 micrograms

There are three types of Vitamin K 

1. Phylloquinone (K1)
2. Menaquinone (K2)
3. Synthetic (K3)

Phylloquinone forms come from plant sources and the menaquinones are derived from bacterial sources. Synthetic vitamin K is man-made. Both are available in supplemental forms for those who are not getting enough form their diet or who are not able to produce it. The body converts K1 to K2.

“Full spectrum vitamin K” is also available, which is a form that includes both the phylloqinone and menaquinone forms.

Vitamin K and Heart Disease

Arteriosclerosis is one of the most common kiilers in the United States, and the leading contributor to heart attack and stroke. Aging has long been thought to be the main cause of arteriosclerosis.

In the early 1900s, a German pathologist named J.G. Mönckeberg noticed that the middle layer of arteries from heart attacks victims was calcified. At the time, this layer (called the “media”) wasn’t considered important. The attention then was on the inside of the artery, where the hardening wasn’t observed. Although Mönckeberg’s observations went against common knowledge, he offered his opinion that it was involved in heart attack deaths.

Mönckeberg was later proven to be right. Arteriosclerosis (hardening of the arteries), does occurs in the middle layer of the artery where it’s not visible. Arteriosclerosis is associated with aging, and has nothing to do with cholesterol. Instead, it has to do with calcification.

Calcification is just as dangerous as fatty build-up. Japanese researchers fed rats a diet meant to induce calcification. Some of the animals were given 100 mg/kg of body weight of vitamin K, along with the heart attack diet. Others were given 40 mg/kg of vitamin E.

After three weeks, the amount of calcium in the aorta was measured. In the animals that didn’t get the vitamins, calcium levels were much higher. Vitamin K reduced the level of calcium in the aorta and vitamin E reduced it even more. The conclusion was that valve damage from the heart attack diet was reversed by vitamins K and E.

Vitamin K Supplementation

The human body doesn’t store vitamin K. Although the body recycles it, many people are deficient. This is probably due to inadequate diet and a lack of co-factors. Drugs and environmental stress can also place demands on vitamin K reserves.

Green leafy vegetables supply 40-50% of vitamin K for most Americans. Vegetable oils are the next highest source. How much vitamin K people should take is still unknown. The dosage required depends on diet, age and what other stress factors are present. However, it is important to note that vitamin K is not toxic, and, unlike other fat-soluble vitamins, doesn’t accumulate in the body.

If you’re interested in a vitamin K supplement, look for type K1 or K2. Dosages of up to 45mg a day have been used in osteoporosis studies without any ill effect. Vitamin K has been approved in Japan since 1995 for the treatment of osteoporosis. Generally, 10 mg/day is recommended, although you might need mroe depending on your age and life situation.

People taking blood thinners such as Coumadin or heparin shouldn’t take vitamin K without talking to a physician first.

Did you enjoy this post? Why not leave a comment below and continue the conversation, or subscribe to my feed and get articles like this delivered automatically to your feed reader.

Copyright Nutribody