Vitamin K―Protection Against Arterial Calcification & Cardiovascular Disease
Most people get just enough Vitamin K from their diets to maintain adequate blood clotting.
But NOT enough Vitamin K to offer protection against health problems including arterial calcification, cardiovascular disease, osteoporosis, various cancers and brain health problems, including dementia.
The name Vitamin K comes from the German word “Koagulationsvitamin” where its role in blood coagulation was first discovered.
Vitamin K is an essential vitamin. It is one of the four fat-soluble vitamins, along with vitamin A, vitamin D, and vitamin E. It’s found in leafy green vegetables, broccoli, and Brussels sprouts.
Vitamin K and Vitamin K supplements come in several forms and can be confusing. To increase your levels of Vitamin K, it’s important to understand the differences.
Vitamin K Can be Classified as Either K1 or K2
Vitamin K1: Found in green vegetables, K1 goes directly to your liver and helps you maintain a healthy blood clotting system; keeps your own blood vessels from calcifying, and helps your bones retain calcium.
Vitamin K2: Bacteria produce this type of Vitamin K; it goes straight to vessel walls, bones and tissues other than your liver. It is present in fermented foods, particularly cheese and the Japanese food natto (the richest source of K2).
Different Forms of Vitamin K2
Making matters even more complex, there are several different forms of Vitamin K2. MK-4 and MK-7 are the two most significant forms of K2 and act very differently in your body.
MK-4 is a synthetic product, very similar to Vitamin K1, and your body is capable of converting K1 into MK4. It has a very short biological half-life of about one hour, making it a poor candidate as a dietary supplement. It remains mostly in your liver where it is useful in synthesizing blood-clotting factors.
MK-7 is a newer agent with more practical applications because it stays in your body longer; its half-life is three days, meaning you have a much better chance of building up a consistent blood level, compared to MK-4 or K1. It slows down cardiovascular aging and osteoporosis, and prevents inflammation by inhibiting pro-inflammatory markers produced by white blood cells.
Food Sources of Vitamin K and MK-7

Photo by Like_The_Grand_Canyon on Flickr licensed CC-BY
MK-7 is extracted from the Japanese fermented soy product called ‘natto’. You get loads of MK-7 from natto. However, natto is generally not appealing to a Westerner’s palate (can’t tolerate its smell and slimy texture).
You can also find Vitamin K2, including MK-7, in other fermented foods including some fermented vegetables.
Certain types of fermented cheeses (Jarlsberg) are high in K2 but others are not. It really depends on the specific bacteria. You can’t assume that any fermented food will be high in K2.
Besides broccoli, Brussels sprouts and leafy green vegetables (kale, mustard greens, collard greens, raw Swiss chard, spinach), other foods high in Vitamin K include beef liver, pork chops and chicken, prunes and Kiwi fruit, soybean and canola oil.
Vitamin K Supplements
Choosing a K2 supplement: When supplementing your Vitamin K food sources, consider a high quality MK-7 form of vitamin K2. (Plus, as they are inexpensive, include Vitamin K1 and MK-4 to help inhibit and possibly reverse vascular calcification.)
Dosage: Although the exact dosage of Vitamin K is yet to be determined, one of the world’s top Vitamin K researchers, Dr. Cees Vermeer recommends between 45 mcg and 185 mcg daily for normally healthy adults.
My choice: I’m taking Relentless Improvement Vitamin K2 MK4 Plus MK7; Read about it on Amazon.com. David Holzman writes that he uses Whole Foods Vitamin K2 which is less expensive. (Use our portal link to Amazon.com and support A-Fib.com)
(If you have a K2 supplement recommendation, email me.)
Remember!
Always take your Vitamin K supplement with food that contains fat
since it is fat-soluble and won’t be absorbed without it.
Read more about mineral deficiencies and Atrial Fibrillation, see FAQs: Mineral Deficiencies & Supplements for a Healthy Heart
This article is based on Dr. Mercola’s article, New Study Shows Evidence That Vitamin K2 Positively Impacts Inflammation.