A Very Special K
All in all, it’s a pretty special vitamin—and not just for its blood-clotting ability or its role in supporting bone health and heart health. Vitamin K also benefits healthy blood sugar levels.
Here’s the lowdown: People with a higher dietary intake of vitamin K—especially vitamin K2—are significantly less likely to develop Type 2 diabetes, according to a study published in the journal Diabetes Care.
But let’s back up the train a little bit.
Vitamin K refers to fat-soluble compounds called anphthoquinones. Vitamin K1, also called phylloquinone, is the natural, plant form of this nutrient, while vitamin K2, which goes by the name menaquinone, comes from healthy bacteria in the human gut as well as certain foods. Vitamin K3, called menadione, is the synthetic version of vitamin K.
Vitamin K1 is found primarily in dark-green vegetables like spinach and broccoli as well as fruits such as kiwi and avocados. In fact one serving of spinach or two servings of broccoli provide four to five times the RDA of K1, and most people do not get enough of this kind of vitamin K.
Vitamin K2 is found in meat, eggs and dairy products, and is also synthesized by the human body. K2 is the vitamin K that strongly supports bone and heart health, although K1 does as well. But there’s more to this special K—K2.
Vitamin K2 can be further categorized, including the MK-4 or the MK-7 variety. Most vitamin K found in the Western diet is of the MK-4 variety, but MK-7 is the most readily metabolized form of K2. It can be found most abundantly in natto, a fermented soy dish that’s part of the traditional Japanese diet. Natto is an acquired taste, though, so other sources of MK-7 include fermented foods like sauerkraut, fermented cheeses and dairy foods like grassfed butter and organ meats.
Interestingly, inadequate healthy intestinal bacteria supplies can keep a person from properly assimilating K2, so it’s a good idea to make sure your intestinal bacteria is sufficient by including plenty of fermented, probiotic-rich foods.
As far as K1 and K2 and blood sugar health, researchers found that both forms of vitamin K can support healthy levels of blood sugar. K2, however, is required in a lesser amount than K1 is. In short, vitamin K1 was needed at very high amounts to decrease diabetes risk, while each 10 microgram increase in vitamin K2 led to a decrease in diabetes risk.
Other benefits of this special K—K2—is that it is an excellent calcium regulator, able to move excess arterial calcium into bone tissue where it belongs and is needed, while removing it from the arteries where it doesn’t belong. Additionally, a shortfall of vitamin K2 can lead to arteriosclerosis and osteoporosis, while adequate K2 intake can support skin, brain and prostate health.
Pretty special, huh?