Vitamin K2 – the short version
Science strongly shows that vitamin K plays an integral part in bone health, cardiovascular health, hormone health, insulin sensitivity, energy, gene expression, and cancer prevention. Osteoporosis accounts for more hospital days than diabetes, heart attacks, and breast cancer.
Vitamin K2 is a specific form of vitamin K that is found in animal products and fermented foods, as opposed to vitamin K1 that’s found in green-leafy plant foods. There are multiple observational studies that suggest that higher vitamin K2 intakes is beneficial. In humans, Vitamin K2 is more effective at activating the systems that we’ve been talking about than vitamin K1. In fact, humans are poor converters of vitamin K1 to K2. If you look at vitamin K2 intakes, people who are in the highest — depending on the study, are likely to have better bone mineralization, a lower risk of heart disease and blood vessel calcification and also a lower risk of multiple different types of cancer. The liver synthesizes bile acids and secretes them into the small intestine where they play a critical role in absorption of lipids. Vitamin K, as a fat-soluble vitamin, requires proper lipid absorption for its own absorption. Liver disease and the like resulting in decreased bile salt synthesis leads to impaired vitamin K absorption and deficiency.
There are studies showing that in children, you can reverse that increase in the fracture risk during critical periods with vitamin K supplementation. Likewise, there are successful vitamin K interventions Japan, in the elderly, where very high doses, caused a dramatic decrease in osteoporosis risk that was more effective than osteoporosis drugs; there were no reported adverse effects.
But how do we get vitamin K in the first place? If you look at what you’re going to get from food, the highest intakes of vitamin K2 tend to be topping out at about 200 micrograms a day. Most people do not get that, but you could find that among people who are eating whole foods. In the Japanese trials they were using 45 mg, a microgram is a thousandth of a milligram. You’re talking about a magnitude one thousand times higher than what you could get from food. But vitamin K2 from food may be more important than getting it from a pill. Most people get their vitamin K2 directly from cheese. Gouda cheese, originally from the Netherlands, is a reasonable source of vitamin K2.
Triage theory and vitamin K
With respect to vitamin K metabolism that, Dr. Ames’ triage theory is pretty well known. The triage theory hypothesis is accepted among the leading vitamin K researchers probably most would consider it a very valuable tool in understanding vitamin K metabolism.
The triage theory is an idea of priorities. It is the body prioritizing acute survival needs over maintenance of long term health when the supply of nutrients in compromised. In the case of vitamin K what we see is that if that you are inadequate in vitamin K then your liver seems to get top priority to activate blood clotting factors and the bones and blood vessels and all these other systems that are dependent on vitamin K, lose out.
That’s the rational decision of the body saying, “Look, if I get cut and bleed to death that’s much more of an imminent risk than if twenty or thirty years down the road I get arterial plaque, or a heart attack, or a stroke, or osteoporosis with this slow degeneration of the bone matrix.” So there is pretty good evidence that the body does prioritize vitamin K function.