A number of recent studies have contributed to expanding our understanding of vitamin K. We've known that it's essential for bone density and heart health for a long time (1-3). More ways to optimize the benefits of vitamin K have been discovered. This is something that's helped researches create a more biologically-active vitamin K formula.
Vitamin K in Food
It's been identified by scientists that different forms and amounts of vitamin K are present in foods. This provides crucial insights into the different types of vitamin K we should be consuming.
It also shines light on certain limitations in relying on foods to supply us with the types and levels of vitamin K associated with peak bone and cardiovascular health.
Vitamin K Forms
In food, vitamin K comes in two general forms:
- Vitamin K1 (or phylloquinone) - primarily found in leafy green vegetables
- Vitamin K2 - primarily found in Japanese nattō or fermented soy, and in animal products such as eggs, meat, milk and cheese (6).
Vitamin K2 has several subtypes that are denoted by a number, e.g. MK-4, MK-6 and MK-7. MK is short for menaquinones. These are vitmain K forms that vary in their organic structure.
MK-7 is a long-acting vitamin K form that's been available over-the-counter as a dietary supplement for many years. It's only just recently that MK-9 has become available in supplement form.
Limitations to Vitamin K Intake Via the Diet
Studies show that there are certain problems in relying on diet to supply all the various forms of vitamin K. Vitamin K1 found in foods has a low bioavailability (8). What this means is that even if you might eat a very large amount of leafy green vegetables, you may not actually absorb adequate amounts of vitamin K1.
Vitamin K2 is found in the highest concentrations in many foods that people to limit their intake of, e.g. foods that are high in saturated fat (9). You would have to consume massive amounts of cheese to achieve the optimal vitamin K2 levels that are supported by human clinical trials. Lower-fat versions of these very foods often have far less vitamin K2 in them - if any at all (9).
Supplementation is a more efficient and practical way of increasing your vitamin K intake, but what doses of the different forms of vitamin K are the optimal ones that we should be consuming daily?
WHAT YOU NEED TO KNOW
Broad-Spectrum Vitamin K
- Vitamin K is an essential vitamin found in two general forms of K1 and K2
- Research has found that vitamin K is not only important for coagulation (blood clotting), but also for bone- and cardiovascular health
- Research has also been instrumental in clarifying the ideal doses of vitamin K1 and K2 necessary for optimization of bone- and heart health.
Because the foods that contain the most vitamin K naturally often have poor bioavailability and high fat content, relying solely on the diet to supply adequate amounts of vitamin K is most likely not the best idea.
The Role of Vitamin K in Bones and Blood Vessels
The effect that vitamin K has on the production of coagulation factors for normal blood clotting has been well understood and demonstrated, but it's only just recently that research has revealed the impact it has on bones and blood vessels.
Several vitamin K-dependent proteins have been discovered in both bone and blood vessels. This means that they require adequate vitamin K levels to function properly (2,3).
Vitamin K is essential for the production of active osteocalcin, which is a hormone that plays a large role in the formation of new bone, and is often used as a biochemical marker of overall skeletal health.
Vitamin K supports calcium deposition in bone. In blood vessels, vitamin K has the exact opposite effect; helping prevent excess calcium deposition. Calcification in arteries is common in elderly people and is associated with arterial stiffening, atheosclerotic plaque and increased risk of heart- and kidney disease (3).
Vitamin K is an essential nutrient that's being recognized for more health benefits than simply aiding in coagulation. Scientific research demonstrates the fact that adequate vitamin K intake is crucial for optimal bone-, heart valve- and blood vessel health. Recent studies have shined a light on the importance of new vitamin K forms associated with reduced risk og age-related outcomes.
Applying this knowledge, scientists have created a broad-spectrum vitamin K, formula, with beneficial MK-6 and MK-9 compounds, alongside K1, MK-4 and MK-7.
- Akbari S, Rasouli-Ghahroudi AA. Vitamin K and Bone Metabolism: A Review of the Latest Evidence in Preclinical Studies. Biomed Res Int. 2018;2018:4629383.
- Villa JKD, Diaz MAN, Pizziolo VR, et al. Effect of vitamin K in bone metabolism and vascular calcification: A review of mechanisms of action and evidences. Crit Rev Food Sci Nutr. 2017 Dec 12;57(18):3959-70.
- Wen L, Chen J, Duan L, et al. Vitamin Kdependent proteins involved in bone and cardiovascular health (Review). Mol Med Rep. 2018 Jul;18(1):3-15.
- Geleijnse JM, Vermeer C, Grobbee DE, et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004Nov;134(11):3100-5.
- Hao G, Zhang B, Gu M, et al. Vitamin K intake and the risk of fractures: A meta-analysis. Medicine (Baltimore). 2017 Apr;96(17):e6725.
- Maresz K. Proper Calcium Use: Vitamin K2 as a Promoter of Bone and Cardiovascular Health. Integr Med (Encinitas). 2015 Feb;14(1):34-9.
- Gast GC, de Roos NM, Sluijs I, et al. A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis. 2009 Sep;19(7):504-10.
- Gijsbers BL, Jie KS, Vermeer C. Effect of food composition on vitamin K absorption in human volunteers. Br J Nutr. 1996 Aug;76(2):223-9.
- Fu X, Harshman SG, Shen X, et al. Multiple Vitamin K Forms Exist in Dairy Foods. Curr Dev Nutr. 2017Jun;1(6):e000638.
- Brandenburg VM, Reinartz S, Kaesler N, et al. Slower Progress of Aortic Valve Calcification With Vitamin K Supplementation: Results From a Prospective Interventional Proof-of-Concept Study. Circulation. 2017 May 23;135(21):2081-3.
- Available from: https://www.cardiosmart.org/heartvalvedisease. Accessed March 8, 2019.
- Available from: https://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2626/2. Accessed March 8, 2019.
- Koitaya N, Ezaki J, Nishimuta M, et al. Effect of low dose vitamin K2 (MK-4) supplementation on bio-indices in postmenopausal Japanese women. J Nutr Sci Vitaminol (Tokyo). 2009 Feb;55(1):15-21.
- Koitaya N, Sekiguchi M, Tousen Y, et al. Low-dose vitamin K2 (MK-4) supplementation for 12 months improves bone metabolism and prevents forearm bone loss in postmenopausal Japanese women. J Bone Miner Metab. 2014 Mar;32(2):142-50.
- Available from: https://www.nof.org/preventing-fractures/general-facts/what-women-need-to-know/. Accessed March 8, 2019.
- Knapen MH, Braam LA, Drummen NE, et al. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial. Thromb Haemost. 2015May;113(5):1135-44.
- Knapen MH, Drummen NE, Smit E, et al. Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women. Osteoporos Int. 2013 Sep;24(9):2499-507.
- Beulens JW, Bots ML, Atsma F, et al. High dietary menaquinone intake is associated with reduced coronary calcification. Atherosclerosis. 2009 Apr;203(2):489-93.
- Kumar R, Binkley N, Vella A. Effect of phylloquinone supplementation on glucose homeostasis in humans. Am J Clin Nutr. 2010 Dec;92(6):1528-32.
- Nakamura E, Aoki M, Watanabe F, et al. Low-dose menaquinone-4 improves gamma-carboxylation of osteocalcin in young males: a non-placebo-controlled dose-response study. Nutr J. 2014 Aug 27;13:85.
- Rasekhi H, Karandish M, Jalali MT, et al. The effect of vitamin K1 supplementation on sensitivity and insulin resistance via osteocalcin in prediabetic women: a double-blind randomized controlled clinical trial. Eur J Clin Nutr. 2015 Aug;69(8):891-5.
- Theuwissen E, Cranenburg EC, Knapen MH, et al. Low-dose menaquinone-7 supplementation improved extra-hepatic vitamin K status, but had no effect on thrombin generation in healthy subjects. Br J Nutr. 2012 Nov 14;108(9):1652-7.
- Cockayne S, Adamson J, Lanham-New S, et al. Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2006 Jun 26;166(12):1256-61.