Why Vitamin K is an Essential Nutrient for Women

Calcium should stay in the right place


How do heart and bone health interact? The answer is calcium. Calcium belongs in the bones, not in the arteries. Very often heart disease occurs when calcium gets stripped from bone and deposited on the arterial walls. This results in what we call arterial calcification (a hardening of the arteries). Meanwhile, when calcium leeches out of the bones, the bones themselves get thinner and weaker: a condition known as osteoporosis.

Clearly, heart disease (and stroke) are directly linked to the amount of calcium floating around in the blood – calcium which ought to be in your bones.  Do you remember playing on a seesaw as a child? Imagine a seesaw with a normal-sized kid on one end and a teeny little guy on the other.  That seesaw will be locked in one direction. In the body, it is similar. Some metabolic deficiency (little kid) might create an imbalance, and cause calcium to leech out of your bone matrix and coat the lining of your arteries. We all need to avoid this, and maintain our strong bones and supple arteries.



Anti-Aging Basics

Without doubt, two of the most obvious signs of advanced aging are a weak heart and brittle bones. So it is only logical to focus on preventive medicine to combat these two problems. Post-menopausal women are particularly at risk as a consequence of hormonal changes affecting their metabolism. Although female incidence of heart disease still trails that of men, there are recent signs of acceleration amongst women’s rates. It is advisable for any woman in today’s world to consider heart health and osteoporosis prevention as two sides of the same challenge. And research teams both in Japan and in the US have correlated both types of disease with extremely low blood levels of Vitamin K.

Standard medical thinking has been puzzled by the simultaneous occurrence of arterial calcification and osteoporosis, calling it the “calcification paradox”.  Actually, it is not a paradox at all. It is simply calcium going from the right place into the wrong place. Many factors can cause this problem including environmental toxins, parathyroid problems, parasites, food additives and flavor enhancers, over consumption of soda, and acidic diets. But Vitamin K is an absolutely key player in protecting us, and in reversing possible damage to the body.


What Should You Do?

There are several key nutrients you want to make sure are in your diet (in the right amount) to avoid heart problems, osteoporosis or osteopenia (a milder form of osteoporosis). I will focus on each of these essential nutrients in different postings. There are also important herbs, teas, exercises and meditations which are very beneficial for healing either the heart or the skeleton. But today we will talk about Vitamin K.


What is Vitamin K?

Like many other vitamins, Vitamin K is a group of substances with several members. They used to be given numbers (Vitamin K1, Vitamin K2, Vitamin K3 etc.)  More recently, Vitamin K has been re-classified as two  sub-groups belonging to the main K group of naphthoquinones.

The first of these sub-groups are the phylloquinones. They used to be known as Vitamin K1. They are found in plant foods, especially dark leafy greens. This group has long been known to be vital for normal blood clotting.

The second sub-group is known as the menaquinones. They used to called Vitamin K2. These are derived either from animal products including meats, eggs, butter and cheese, or they are synthesized in the gut by our friendly flora. They are always bacterial in origin and are generated by a type of fermentation. The menaquinones have been recognized as vital for directing calcium into the bone matrix. However, this is also done by cleaning up the blood from circulating calcium, and thus preventing pathologic calcification and concomitant blood clotting. The menaquinones are called MK, and are given numbers. Perhaps the strongest and most important is MK-7. This is formed by the bacteria that ferment soy beans: bacillus natto. An extract from natto, called nattokinase, is often given to people to ensure that their blood flows smoothly and does not become viscous. Viscous blood is unhealthy blood. In Japan, natto has been consumed for generations, and may have much to do with the longevity of the Japanese. MK-7 is also found in a few cheeses, whereas MK-4 is generally found in meats, cheese, butter and eggs.


A Combination of Vitamin K1 and K2 is Best

It has long been recognized that Vitamin K is important for bone health, but only later did researchers explore its relationship with cardiovascular health. A groundbreaking report, published in the Netherlands in 2004, the Rotterdam Study, concluded that Vitamin K played a significant role in arterial health, and that different types of this Vitamin had different effects. The Rotterdam Study’s authors stated that it was K2, the menaquinones which protected the arteries from calcification, by driving the calcium into the bone matrix.

However, more recent research has indicated that, contrary to earlier theories, the phylloquinones (aka Vitamin K1) also play a vital role in preventing atherosclerosis and arterial calcification.  A study published in 2009 compared a group of 200 people given phylloquinone supplementation with a control group of 188. The researchers showed the phylloquinone group to have significantly less evidence of coronary arterial calcification than the control group had.

So phylloquinone (aka K1) also protects your heart, and keeps that calcium from straying out of your bones. The implication is clear: you want to ensure you have adequate amounts of both K1 and K2 in your diet.


Dietary Sources of Vitamin K1 and K2

Dark leafy greens are the best source of phylloquinones. So Popeye is your role model – but preferably consume your spinach fresh, not out of a can!

King of the pile is Kale (1,062 micrograms), followed by spinach (888mg), collard greens ( 704mg), chard (572 mg), and turnip greens (529mg). Kale is a truly remarkable food which comes in many varieties, including purple kale and dinosaur kale. It can be made into delicious soups, fresh juices combined with apple, or fresh salads, cut fine and marinated in lemon juice and garlic.

On the menaquinone side, if you are a vegan, you may be depriving your body of this important nutrient. Ironically, vegans who consume no dietary cholesterol may induce coronary arterial diseases because they have no menaquinones (K2) in their diet. This is particularly important for post-menopausal women: veganism is not likely to give you the full range of nutrients your body needs.

The strongest source of menaquinone is from natto, or from taking nattokinase. Fermented soy and several cheeses are likely to provide you with menaquinone (K2) as well.

Don’t forget that menaquinone is also made in the body by the friendly bacteria in your intestines. If you have recently taken antibiotics, if you take a lot of antibiotics in the past, or frequently take pharmaceuticals, if you are a heavy drinker, or consume a generally unhealthy diet, it is very likely that your friendly flora are suffering. You will need to change this and rebuild the acidophilus, bifidus and other probiotic strains in your gut. Those little guys are keeping you alive, supporting your immune system and pumping out Vitamin K2, the menaquinones.



If you are taking multi-vitamin supplements, you should check to see that Vitamin K is part of the formula. It may specify K1 and K2, or it may say MK4 and MK7. Whatever it says, you should make sure you are getting both varieties of K. Especially if you are at risk for osteoporosis, it is important to consult with your health-care professional to evaluate your overall dietary intake of Vitamin K.