Since 1995, high doses of vitamin K2 supplements have become an approved treatment for osteoporosis in Japan, where studies support its benefit in preventing further decrease in bone mineral density. Some women have experienced an increase in bone mass as a result of this intervention.1 While these results are promising, more studies are needed to confirm their applicability to other populations. Of the menaquinones, MK-4 and MK-7 are the most studied, says Erika Zoellner, a senior registered dietitian at Baylor College of Medicine. They are usually related to bone health and cardiovascular health, but more research is needed to fully understand the benefits and mechanisms of these menaquinones. Although vitamin K1 is usually the primary dietary source of vitamin K and is mainly found in leafy greens, vitamin K2 remains an important part of a balanced diet and is mainly found in animal and fermented foods. Vitamin K refers to a family of fat-soluble vitamins that the body needs to produce a protein called prothrombin, which promotes blood clotting and regulates bone metabolism.
In fact, mgP relies on vitamin K for its functions, and this protein prevents calcium from being deposited in blood vessels and other soft tissues. To support this mechanism, several observational studies have linked higher intakes of vitamin K2 to lower coronary calcification. Often confused with vitamin K1 or simply overlooked, vitamin K2 is a unique form of an essential micronutrient that plays an important role in heart health. Let’s see how much vitamin K2 you need, where to get it, and its potential benefits and side effects.
Vitamin K1, phylloquinone, helps with blood clotting and is mainly found in leafy vegetables such as spinach, kale, kale and broccoli. Vitamin K2, menaquinone, is the form produced by gut bacteria and is found in natto and some fermented cheeses and animal products. Unlike its vitamin K1 counterpart, vitamin K2 is rare in the Western diet and therefore has not received much general attention. However, emerging research shows that vitamin K2 may play an essential role in preventing bone loss, improving vascular health, and reducing the risk of cancer. In fact, the Food and Nutrition Board of the National Academies hasn’t even indicated an upper limit for vitamin K1 or K2. This is because no adverse effects of any of the forms of vitamin K in humans or animal models have been documented when consumed through food or supplements.
In liver tissue, apoproteins such as apoE help bind lipoproteins to their receptors, making them act as a ligand for the internal absorption of the remnants of these lipoproteins. It is the same mechanism that causes the absorption of vitamin K in liver tissue, which is evident by the detection of breakdown products in both bile and urine. Research on vitamin K absorption in bone revealed similar findings of elevated apoE levels, suggesting the presence of lipoprotein receptors in osteoblasts. This correlated with a decrease in levels of non-carboxylated osteocalcin, meaning vitamin K must have been actively included in the bone matrix.
The richest source of MK-7 comes from bacterially fermented foods, such as natto, a traditional soy dish commonly found in Japan. The production of Natto is a challenge due to the specific measures required for cereals and the difficult fermentation process; this may explain the scarcity of this type of food in the diets of other countries. This increased intake of vitamin K2 in the diet of the Japanese population has led to fundamental studies on its beneficial effects on calcium metabolism, especially since it correlated with a lower incidence of osteoporosis. Research is ongoing to clarify whether the Western diet currently contains a viable amount of vitamin K2, as it is only found in certain foods. Other food sources rich in vitamin K2 include egg yolks, hard-boiled cheeses, cottage cheese, butter and sauerkraut. Because both vitamin K1 and K2 are produced by plants, both are commonly found in the intestinal tract due to the presence of fermenting bacteria.
Apparently, there is only one short-term effect of giving MK-7 to healthy individuals. Many conditions are closely related to vascular calcification, including hyperlipidemia, chronic kidney disease and diabetes. These diseases can increase the risk of calcification and formation of atherosclerotic plaques. A study in hemodialysis patients showed an increase in MK-7, resulting in decreased levels of non-carbylated osteocalcin and MGP, but only with adequate intake of vitamin K2.
It also reduced cases of coronary heart disease by 41%, severe arterial calcification by 52%, and total mortality by 36%. Remember that vitamin K2 is essentially the “messenger” that directs calcium to all the right places while avoiding the wrong places like our arteries. Supporting a healthy gut microbiome, consuming foods rich in menaquinone, and including a vitamin K supplement are three practical ways to ensure that you include this important form of vitamin K in your life. When taking anticoagulant medications, it is important to keep vitamin K intake stable.
Since this discovery, research on the subject has blossomed, which has resulted in the collection of a large amount of information, allowing for a better understanding of the vitamin. Evidence has elucidated its vital role in the clotting pathway, with more recent research on the effect it has on extrahepatic processes in the body. In particular, vitamin K2 has been shown to have a significant effect on calcium metabolism. Vitamin K as a family plays a crucial role in blood clotting, and that’s how the nutrient got its name. The good news is that K2 is effective in the small doses you can get in your diet, so there’s no real need for supplementation when you consume K2-rich foods. Additionally, by eating fatty meats, organ meats, whole dairy, and grass-fed eggs, you get the added benefit of eating whole foods that provide synergistic nutrients D and K, along with complete proteins and healthy fats.
However, the two main forms available in supplement form are menaquinone-4 (MK-4) and menaquinone-7 (MK-7),2 Mk-4 is rare as a supplement because it has such a short viable shelf life. Therefore, your body has a limited window to make use of the nutrient and eventually has to take several doses a day to make it worthwhile. As such, if you buy a K2 supplement, chances are you’re buying menaquinone-7, so we’ll focus the rest of the discussion on MK-7. In another study, postmenopausal women who ate more natto, a Japanese dish made from fermented soy and the richest food source of vitamin K2, experienced less bone loss over time. Of course, before taking a new supplement, it’s always a good idea to first discuss your health history with your doctor. Depending on your needs and current diet, adding a vitamin K2 supplement may be helpful in reducing the risk of cardiovascular incidents and bone fractures.
This leads to calcification of blood vessels, which can lead to heart disease or stroke. But it is important to ask whether the rate of bone fractures is reduced with an natural vitamin k2 increased intake of vitamin K through the diet. Research has helped establish dosage levels that maximize the benefits of the MK-4 form of vitamin K2 on bone health.