Understanding the importance of Vitamin K2 to support healthy bones and circulation

Now more than ever, we’re taking notice of our health with exercise, health care check ups and balanced diets/supplements. The result is that individuals are living longer than ever.  The idea of optimum health however is less about living longer, but more about living better.

To achieve this, many are trying to ensure that they don’t suffer any nutritional insufficiencies. Even with a virtuous and balanced diet however, there are some vitamins we just don’t get enough of from the diet, including vitamin K2. Vitamin K2 supplements are growing in demand, mainly because of the nutrient’s incredibly protective benefits to bones and the circulation.

Who can benefit?

K2 is beneficial to anyone who wants to help take care of their bone and circulatory health and help protect these systems for future years. Many are vitamin K2 deficient as it rarely occurs in western diets. The main dietary K2 source is natto, a traditional Japanese dish of fermented soy beans rarely eaten outside of Japan (and even in Japan, is considered an acquired taste).

Low vitamin K levels can also result from poor diet, alcoholism, malabsorption disorders, ageing, and certain medicines. Interestingly, statin medications (a common prescription for cholesterol control) have been shown in studies to deplete K2 levels in the body (1).

How does it work?

Vitamin K2 aids in the maintenance of normal bones and circulation by its key role in the activation of proteins osteocalcin (OC) and matrix Gla-protein (MGP). These proteins help ensure that calcium is deposited into bones, not into blood vessels: an important consideration for anyone taking calcium supplements or who has large dietary calcium intakes.

Circulatory Health

As mentioned, K2 activates MGP which found in blood vessel walls.  Activated MGP binds calcium and helps ensure it is not deposited into blood vessels. This calcification would otherwise lead to blood vessel hardening, a build of plaque, elevated blood pressure and cardiovascular risk.

A 2004 population study with 4807 subjects showed that individuals with adequate vitamin K intakes experienced reduction in:

  • CVD and death from CVD
  • Severe calcification of the blood vessels
  • All cause mortality

The lead researcher discussed that this effect may be due to reduction in arterial calcification, and suggests that elevated intakes of vitamin K2 may contribute to heart disease prevention (2).

Bone Health

From 30-35 onwards, we begin to lose bone mass which can eventually lead to brittle and fracture prone bones. Known as osteoporosis, this is thought to effect one and three women, and one and five men globally.

Osteopenia/osteoporosis is even  more pronounced for post-menopausal women due to falling oestrogen levels (which would otherwise have bone sparing benefits).

Vitamin K2 assists by activating osteocalcin, enabling calcium to be incorporated into the bones and contributing to bone density. K2 also inhibits the activity of osteoclasts, cells which naturally break down bone as part of bone homeostatis.

K2: Synergistic with Vitamin D and Calcium

Vitamin D (which has been in the headlines a lot lately) is associated with improving bone density and is typically coupled with calcium.  What’s lesser known however, is how  vital vitamin K is to this process as well; calcium is less likely to ever each the bone matrix without adequate K.

Vitamin D increases the intestinal uptake of calcium from the gut, but also induces the synthesis of osteocalcin which, as previously mentioned, requires adequate vitamin K to activate!

Why forms Matter: MK4 vs MK7

K2 is available in many homologues known as menaquinones, with menaquinone-4 (MK-4) and menaquinone-7 (MK-7) being the most popular in supplements. MK-4 has evidence supporting its use in bone and circulation health and has traditionally been the most studied. MK-7 has vastly become the most popular isomer however due to demonstrating more favourable characteristics in studies.

As well as having a longer isoprenoid chain, MK-7 also has a longer half life (72 hours half-life approximately,) meaning it is biologically active in the body for longer than both Vitamins K1 and K2 MK-4. Not only this, studies have shown that MK-7 demonstrates superior effects on normal blood coagulation compared to MK-4 (3) and provides a more active grade of osteocalcin than Vitamin K1(4).

Comparative to MK-4, MK-7 has demonstrated superior uptake and subsequently a raised serum levels in subjects. In one particular study comparing two randomized groups taking 60 μg/day of K2 MK-4 or K2 MK-7, the MK-7 group’s level of K2 had risen significantly, whereas the MK-4 group’s K2 levels did not rise during the seven-day study(5).

Not all K2 MK-7s are equal

Vitamin K2 MK-7 supplements may be either be processed via fermentation or via a patented organic process. K2 MK-7 produced via the organic process demonstrates a 100% trans MK-7 isomer profile. In essence, MK-7 produced this way is 100% biologically active, whereas MK-7 produced via fermentation processes can be a mix of both trans and cis forms (cis being inactive).

This organic process produces K2 MK-7 which is free of common allergens, great news for individuals adverse to soy present in the fermented varieties.  As a lipid soluble vitamin, K2 is best absorbed from the gut in the presence of fats, most dependably in an oil capsule format.

K2- the next step in preventative nutrition

The importance of vitamin K2 is being noticed, with more individuals opting to take advantage of its bone and circulatory health benefits.  Difficult to derive from food, careful consideration should be made when opting for which vitamin K2 to choose to get the best out of the supplement. The research is clear;  Vitamin K form matters!

Okuyama H e. Statins stimulate atherosclerosis and heart failure: pharmacological mechanisms. – PubMed – NCBI [Internet]. Ncbi.nlm.nih.gov. 2017 [cited 10 April 2017]. Available from: https://www.ncbi.nlm.nih.gov/pubmed/25655639
Geleijnse J, Vermeer C, Grobbee D, Schurgers L, Knapen M, Meer I et al. Dietary Intake of Menaquinone Is Associated with a Reduced Risk of Coronary Heart Disease: The Rotterdam Study [Internet]. Jn.nutrition.org. 2017 [cited 10 April 2017]. Available from: http://jn.nutrition.org/content/134/11/3100.long
Bioavailability of phylloquinone and menaquinones after oral and colorectal administration in vitamin K-deficient rats – ScienceDirect [Internet]. Sciencedirect.com. 2017 [cited 10 April 2017]. Available from:http://www.sciencedirect.com/science/article/pii/000629529500202B?via%3Dihub
Schurgers L, Teunissen K, Hamulyak K, Knapen M, Vik H, Vermeer C. Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7. 2017.
Sato T, Schurgers L, Uenishi K. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutrition Journal. 2012;11(1).
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