Tag Archives: vitamin K

The vitamin K family and bone health

The holidays are that time of year for family gatherings. Some of us have big families while some of us have small families. The much ignored(until recently) vitamin K is actually a big family and not just one lonely vitamin. In this respect, it is similar to the B vitamin complex, which is made up of several distinct vitamins under the vitamin B umbrella, all of which are needed for proper energy metabolism.

So what is so special about vitamin K? Vitamin K, which is fat-soluble, is essential for blood clotting(coagulation), as well as optimal calcium metabolism. A deficiency of vitamin K can lead to excessive bleeding. Unfortunately for vampires, vitamin K deficiency is rare.

Phylloquinone chemical structure

Phylloquinone chemical structure


Menaquinone chemical structure

Menaquinone chemical structure

There are two main forms of vitamin K – vitamin K1(phylloquinone), and vitamin K2(menaquinone). Vitamin K1 is found mostly in plants while vitamin K2 is found more in meat and produced in the body. This gets even more fun when you consider that there are also many sub-forms of menaquinone, which seem to have somewhat different effects. The overall effect of vitamin K is the synthesis of proteins needed for proper coagulation and the proper metabolism of calcium and bone tissue. This makes vitamin K important both for bone growth and maintenance, as well as the prevention of arterial calcification.

According to Schurgers LJ, Cranenburg EC, Vermeer C. at Maastricht University:

Among the proteins involved in vascular calcium metabolism, the vitamin K-dependent matrix Gla-protein (MGP) plays a dominant role. Although on a molecular level its mechanism of action is not completely understood, it is generally accepted that MGP is a potent inhibitor of arterial calcification. Its pivotal importance for vascular health is demonstrated by the fact that there seems to be no effective alternative mechanism for calcification inhibition in the vasculature. An optimal vitamin K intake is therefore important to maintain the risk and rate of calcification as low as possible.

So vitamin K looks very promising as a treatment for calcification of the arteries(a very common problem among the elderly). Basically, the vitamin K family ensures calcium goes where it belongs(the bones), so it doesn’t get stuck where it can cause problems(the arteries).

According to the same vitamin K researchers quoted above:

Prolonged sub-clinical vitamin K deficiency is a risk factor for osteoporosis, atherosclerosis, and cancer. Present recommendations for dietary intake are based on the daily dose required to prevent bleeding. Accumulating scientific data suggests that new, higher recommendations for vitamin K intake should be formulated.

It also appears that vitamin K may help prevent osteoporosis, and surprisingly, cancer. It also says the scientific data suggests new, higher recommendations for vitamin K intake. It doesn’t say exactly how much more, and I am not recommending we all take vitamin K pills. However, if you are at risk for osteoporosis or have atherosclerosis(of which calcification of the vessels plays an important part), it may be a good idea to talk with your doctor about vitamin K.

Vitamin K is also associated with a decreased risk of type 2 Diabetes, according to Diabetes Care:

This study shows that both phylloquinone and menaquinones intakes may be associated with a reduced risk of type 2 diabetes.

So how can you be sure you are getting enough of both forms of vitamin K? Eating a varied diet that includes a lot of green leafy vegetables can help ensure you get enough. Vitamin K is also produced by gut bacteria. So eating fermented food may ensure optimal vitamin K levels. People with chronic gastrointestinal diseases are at a much higher risk for vitamin K deficiency, according to – Am J Clin Nutr. 1985 Mar;41(3):639-43.

Here is some interesting research from Italy on the different biological effects of the various forms of vitamin K:

Vitamin K (vitamin K1 or phylloquinone and vitamin K2, a series of menaquinones [MKs]) is involved in the production of bone and matrix amino acid γ-carboxy-glutamic acid (Gla) proteins, regulating bone and vascular calcification. Low vitamin K concentrations are associated with increased risks of fractures and vascular calcification, and frequent complications in hemodialysis patients. We carried out an observational study to establish the prevalence of vitamin K deficiency and to assess the relationship between vitamin K status, vertebral fractures, vascular calcification, and survival in 387 patients on hemodialysis for ≥1 year. We determined plasma levels of vitamin K compound, bone-Gla-protein, matrix-Gla-protein, and routine biochemistry. Vertebral fractures (reduction in vertebral body height by ≥20%) and aortic and iliac calcifications were also investigated in a spine (D(5) -L(4)) radiograph. Three-year patient survival was analyzed. Important proportions of patients had deficiency of MK7 (35.4%), vitamin K1 (23.5%), and MK4 (14.5%). A total of 55.3% of patients had vertebral fractures, 80.6% had abdominal aorta calcification, and 56.1% had iliac calcification. Vitamin K1 deficiency was the strongest predictor of vertebral fractures (odds ratio [OR], 2.94; 95% confidence interval [CI], 1.38-6.26). MK4 deficiency was a predictor of aortic calcification (OR, 2.82; 95% CI, 1.14-7.01), whereas MK5 deficiency actually protected against it (OR, 0.38; 95% CI, 0.15-0.95). MK7 deficiency was a predictor of iliac calcification (OR, 1.64; 95% CI, 1.03-2.60). The presence of vertebral fractures was also a predictor of vascular calcifications (OR, 1.76; 95% CI, 1.00-3.08). Increased alkaline phosphatase and C reactive protein (CRP), age, and cerebrovascular events were predictors of mortality. Our study suggests that the vitamin K system may be important for preserving bone mass and avoiding vascular calcification in hemodialysis patients, pointing out a possible role of vitamin K in bone and vascular health. Based on our results, we suggest that the general population should also be studied for vitamin K deficiency as a possible cause of both vertebral fractures and vascular calcification.
Copyright © 2012 American Society for Bone and Mineral Research.

So, have you figured out yet which is your favorite form of vitamin K? Don’t stress yourself out over whether or not you are getting enough of the MK7 form of vitamin K or enough phylloquinone. If you don’t have liver problems, or gastrointestinal problems, or if you are not on dialysis and you are young, eat right and get plenty of exercise, you have little to worry about. But if you are at risk for diabetes, osteoporosis or atherosclerosis, speak with your doctor about vitamin K.

Lactic acid is not your enemy

The idea that lactic acid causes muscle fatigue and stiffness during exercise is a stubborn one. It has been discredited by scientific research, but many fitness enthusiasts still see lactic acid as an enemy that interferes with performance.

Not only does lactic acid(which in the body is in the form called “lactate”) not cause muscle fatigue, it is actually used as an important fuel during vigorous exercise.

This myth goes back to the early 20th century, but it was fully discredited only recently.

All this begs the question: What is causing the fatigue and stiffness that was once blamed on lactate? According to researchers at Columbia University, it may be caused by overworked muscles leaking calcium, among many other factors. And acidity in general in fatigued muscles may play a role in stiffness and fatigue, it’s just not the lactate causing most of it.

So what’s the solution? The idea of calcium leakage partially causing muscle fatigue doesn’t mean most people should consume less calcium, as this is a vital mineral(it is possible to get too much, and it can cause problems but this is rare). However, and I am just speculating here, maybe ensuring adequate vitamin K consumption can help prevent this a little, since it helps with calcium metabolism, along with making sure you get enough magnesium. Calcium helps muscles contract, magnesium helps them contract as well as relax; if you have too much calcium in your body relative to the amount of magnesium, this can be problematic(in fact, not getting enough magnesium may be detrimental to your heart).

It is relatively east to get enough magnesium if you eat like a rabbit – lots of leafy greens, nuts, and whole grains. Fermented vegetables are an especially good source of vitamin K. If you are taking calcium supplements, it may be a good idea to take supplements that combine magnesium with the calcium, to counteract the potentially negative effects of calcium. Try discussing this with your doctor or pharmacist.

Proper hydration and making sure you are getting the right amount of electrolytes helps too. I don’t think stretching would help, since just because a muscle is stiff doesn’t mean it needs to be stretched. Increasingly, science is showing that stretching is practically useless for most people.