The extraordinary Vitamin K

All vitamins are equally important, and their absence from our diet can cause nutrient-deficiency diseases.

Vitamins and minerals have their own carriers. Vitamins A, D, E, and K, are the fat-soluble vitamins, and they are carried through our bodies by the same lipoproteins that carry fat. The other vitamins are water-soluble, and are carried by a range of different protein transporters. These transport carrier systems are all tightly controlled — and they need to be if they’re going to get the right nutrients, not to mention all the communicating hormones and signaling substances, to the right cells that need to get the nutrients.

Most of us don’t have enough understanding about many of the vitamins that are critical for our body. For example, vitamin K, which was first identified by Danish Nobel Laureate Henrik Dam in 1929, and has long been associated with proper blood clotting. Since the 1970s much research has been conducted, linking vitamin K to both proper bone formation and to cardiovascular disease.

But actually, it has many more benefits.

Vitamin K are phylloquinone (K1), which is synthesized by plants, and menaquinone (K2), which is synthesized by bacteria. Both forms are useful in the prevention and therapy of osteoporosis, because they play a key role in carboxylating osteocalcin and other bone proteins. Higher levels of vitamin K level in the body can help reduce the risk of fractures.

There are many types of vitamin K2 (menaquinone-4 Mk4), produced during conversion of vitamin K1, for example from food in the gastro-intestinal tract and pancreas. Menaquinone-7 (Mk7) is converted from vitamin K1 in the intestines by gut bacteria — this is one of the reasons why it’s important to maintain healthy gut bacteria.

The best food sources of vitamin K1 are green leafy vegetables, such as lettuce, collards, kale, parsley, and spinach, as well as other vegetables rich in chlorophyll, such as broccoli. Other plant sources include vegetable oils, nuts, and fruits. Animal foods such as meat, eggs, and soft cheeses and butter contain relatively small amounts of vitamin K2 (Mk4).

Although vitamin K2 (Mk7) is rich in natto and fermented soybean food, most of us do not regularly consume this.

Since vitamin K is fat soluble, foods rich in vitamin K should be eaten together with some healthy fats, such as olive oil or grass-fed butter. The effect of vitamin K2 (mk4-mk7) can also increase when it works together with vitamin D3.

Getting enough vitamin K from our diet, and if needed through supplementation, especially vitamin K2 (mk7), can help reduce the symptoms and may even prevent cardiovascular diseases and coronary artery calcification, arthritis, osteoporosis, and can even reduce risk of certain cancers such as prostate and lung cancer.

In addition, vitamin K, as an antioxidant, may reduce neuronal cell death cause by oxidative stress. This means that it can promote longevity.

There’s no documented allergic reactions to vitamins K1 and K2. MK-7 does not display toxicity, and does not concentrate in excess amounts in the liver, unlike other synthetic vitamin K2. However, vitamin K supplements should not be used by patients taking anticoagulants.


Ayda Ersoy is a nutrition and fitness director at The Diet Doc Hawaii. She can be reached at, or (808) 276-6892


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