In 1943 the Nobel Prize went to two Danish Scientists for elucidating the role of vitamin K in blood coagulation. Since that time this fat-soluble vitamin has been linked to heart health, bone health and even brain health. 

I have people in the pharmacy looking for vitamin K based on what they read in magazines and hear on the news.  Before you rush to buy this vitamin supplement, you need to understand how it works and most importantly if you can or need to take it.  Remember I stated that vitamin K is a fat-soluble vitamin. This means that this vitamin gets stored in the body and can accumulate if you take too much of it. This one example of why you should never use a supplement without medical advisement.

To further break it down, you may see different forms of vitamin K on labels. Vitamin K1 (phylioquinone) is the form of vitamin K that is isolated from green plants.  Vitamin K2 is synthesized from bacteria and is more readily absorbed and lasts longer than vitamin K1 in general terms.

Besides calcium and vitamin D, vitamin K is necessary for maintaining healthy bones. This synergistic relationship between vitamin D, calcium and vitamin K has been the subject of many recent studies. A recent link has also been found between cardiovascular disease and osteoporosis. Many articles have been  written about this fine balance of calcium our bodies need.  Calcium deficiency leads to osteoporosis, and an excess of calcium in the blood may increase the risk of atherosclerosis. Our systems need to have a delicate balance of many things besides insulin to function properly.

Some good sources of vitamin K from food are spinach and salad greens which contain more than 300mcg per 100g. Broccoli, brussel sprouts and cabbage contain 100-200mcg of vitamin K per 100mg. Vitamin K2, otherwise known as menaquinone is synthesized by bacteria synthetically and in the digestive tract, and also is found in some types of cheese. Because we can synthesize vitamin K in our bodies, we do not necessarily need to eat foods rich in vitamin K to get enough of it.

Most people should have adequate vitamin K already without needing to supplement but people who are malnourished, have diseases that impair absorption such as Chron’s Disease or consume a lot of alcohol may have problems with vitamin K levels. There are also some drugs that may interfere with vitamin K absorption such as a group of antibiotics known as cephalosporins when taken for a long period of time. Also certain drugs to lower lipids such as cholestyramine may interfere with vitamin K absorption.

Remember too much of a seemingly “good thing” can be bad, and in fact, dangerous. If you have coagulation problems or are on blood thinners such as warfarin, vitamin K can cause serious problems. The best advice will be from your own health care team, and depends on several factors. Adequate vitamin K may be necessary for optimal diabetes control as well, according to some studies.