Vitamin K comes
in two forms, and it is important to understand the differences
between them before devising your nutritional plan of attack.
Types of Vitamin K
can be classified as either K1 or K2:
K1: Found in green vegetables, K1 goes directly to your liver
and helps you maintain a healthy blood clotting system. (This
is the kind of K that infants need to help prevent a serious bleeding
also vitamin K1 that keeps your own blood vessels from calcifying,
and also helps your bones retain calcium and develop the right
K2: Bacteria produce this type of vitamin K. It is present
in high quantities in your gut, but unfortunately is not absorbed
from there and therefore most of it is passed out in your stool.
straight to vessel walls, bones, and tissues other than the
liver. It is present in fermented foods, particularly cheese
and the Japanese food natto,
which is by far the richest source of K2.
even more complex, there are several different forms of vitamin
MK8 and MK9
come primarily from dairy products. MK4 and MK7 are the two most
significant forms of K2, and act very differently in your body:
is a synthetic product, very similar to vitamin K1, and your body
is capable of converting K1 into MK4. However, MK4 has a very
short half-life of about one hour, making it a poor candidate
as a dietary supplement. After reaching your intestines, it remains
mostly in your liver, where it is useful in synthesizing blood-clotting
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 MK4 or K1. MK7 is extracted from the Japanese food
who are interested in getting a supply of vitamin K2 we do have
it in our store.
are similarly encouraging for the benefits of vitamin K to your
In 2004, the
Rotterdam Study, which was the first study demonstrating the
beneficial effect of vitamin K2, showed that those who consumed
45 mcg of K2 daily lived seven years longer than those getting 12
mcg per day.
In a subsequent
study called the
Prospect Study, 16,000 people were followed for 10 years. Researchers
found that each additional 10 mcg of K2 in the diet resulted in
9 percent fewer cardiac events.
There is also
research emerging that vitamin K can help protect against brain
disease. However, it is too early to say exactly what types of damage
it prevents, and how, but it is an area of intense interest to vitamin
K scientists right now.
More Vitamin K into Your Diet
of green vegetables will increase your vitamin K1 levels naturally,
especially kale, spinach, collard greens, broccoli, and Brussels
K2, cheese and especially cheese curd is an excellent source. The
starter ferment for both regular cheese and curd cheese contains
bacteria lactococci and proprionic acids bacteria
which both produce K2. You get the benefits of these bacteria when
you consume them.
of cheese have the same amount of K2, but curd cheese has less fat.
If you eat 100 grams of cheese daily, you get 45 mcg of vitamin
K2, which will lower your risk for heart attack by 50 percent, according
to existing studies.
You can obtain
all the K2 you'll need (about 200 micrograms) by eating 15 grams
of natto daily, which is half an ounce. It's a small amount and
very inexpensive. It'll only shrink your wallet by about two dollars
If you don't
care for the taste of natto, the next best thing is a supplement.
Remember you must always take your vitamin K supplement with fat
since it is fat-soluble and won't be absorbed without it.
You need not
worry about overdosing on K2 people have been given a thousand-fold
increase over the recommended dose over the course of three years
have shown no adverse reactions (i.e., no increased clotting tendencies).
exact dosing is yet to be determined, Dr. Vermeer recommends between
45 mcg and 185 mcg daily for adults. You must use caution on the
higher doses if you take anticoagulants, but if you are generally
healthy and not on these types of medications, I suggest 150 mcg
It is quite
likely that doses of several times that amount are safe for the
average person, but we just lack the research to confirm it at this
D is Vitamin K's Best Friend
makes the point that vitamin K will never be able to do its work
alone. It needs collaborators and vitamin D is an important
There is a
synergistic effect between vitamins D and K.
agents work together to increase MGP, or Matrix GLA Protein, which
is the protein responsible for protecting your blood vessels from
calcification. In fact, MGP is so important that it can be used
as a laboratory measure of your vascular and cardiac status.
If you are
concerned about your bones, you must balance a nutritional triad:
calcium is good for your bones but not so good for your arteries,
which can become calcified. Vitamin K protects your blood vessels
from calcifying when in the presence of high calcium levels. So
you really must pay attention to the synergism of all three of these
nutrients if you want to optimize your benefits.
Testing for Vitamin K is in its Infancy
measurements in blood plasma can be done accurately, but the results
are really not helpful because they mainly reflect "what you
ate yesterday," according to Dr. Vermeer.
are no good laboratory assessments, he and his team have developed
and patented a very promising laboratory test to assess vitamin
K levels indirectly by measuring circulating MGP. Their studies
have indicated this to be a very reliable method to assess the risk
for arterial calcification hence cardiac risk.
They are hoping
to have this test available to the public within one to two years
for a reasonable price, and several labs are already interested.
they are working on developing a home test that would be available
at your neighborhood drug store.
At this time,
however, there is really no commercial test that would give you
meaningful information. But since nearly 100 percent of people don't
get sufficient amounts of vitamin K from their diet to reap its
health benefits, you can assume you need to bump up your vitamin
K levels by modifying your diet or taking a high quality supplement.