The health benefits of Vitamin K2
Osteoporosis, the weakening of the bones due to bone mineral loss, afflicts over two million Canadians, with many more going undiagnosed. The disease is associated with increased bone fractures and a loss of independence. It primarily affects menopausal women. Women can lose an alarming 2-5% bone density per year during menopause.1
When it comes to preventing osteoporosis, no other vitamin or mineral is more closely associated with bone health than calcium. Through Health Canada’s dietary recommendations, advice from our personal health care practitioners and the milk advertisements that we watch on television every day, the connection between calcium and bones is pervasive. Indeed, it is true that calcium is necessary for bone health. Calcium provides the protective “concrete” coating to the collagen “re-bar” of our skeletal structure. Our bones act as a store-house for calcium in the body. Humans, however, are not able to produce calcium – we must get it through our diet.
Because of the high incidence of osteoporosis and osteopenia in the aging population, it is assumed that calcium intake must be increased. Many women are supplementing with 1200 mg of calcium per day to prevent or slow osteoporosis based on the recommendation of their health care practitioner. Newer studies, however, have begun to question whether taking these high amounts of calcium is truly beneficial.
Recently the media has trumpeted such headlines as “Calcium pills taken by hundreds of thousands of women ‘double risk of heart attack and could do more harm than good” (Daily Mail, May 2012), leading calcium users to be concerned about supplementing with this mineral.2 A large study done by the University of Auckland, looking at calcium supplement users in Germany was behind the headlines and suggested that calcium supplements at high doses may indeed be linked to an increased incidence of heart attacks. The study was quite controversial and some felt that more studies need to be done before such conclusions were drawn. The authors of the study concluded that calcium-only supplements in insolation were not as well utilized by the body as calcium from food sources.3
Vitamin D, the sunshine vitamin, has recently received increased attention for its role in bone health. Vitamin D helps us to absorb a higher percentage of our calcium intake. Supplementation of vitamin D is often recommended in Canada, due to our low intake of vitamin D during the short period of daylight in our winters. Vitamin D has its limits, however. While vitamin D increases absorption of calcium, it does not direct calcium to the bones. Yet another specialized vitamin is required to increase the uptake of calcium in the bones.
The Vitamin K2 Factor
While many have increased their calcium intake, the incidence of osteoporosis and cardiovascular incidents has also continued to rise. Emerging – and often ignored– research, is revealing that our intake of another much needed bone nutrient has decreased: vitamin K2.
Vitamin K2, a fat soluble vitamin, was once naturally abundant in our diets. It was found in the animal byproducts that we consumed daily, such as meat, eggs, dairy and cheese. Animals consume vitamin K1 from the grass that they eat while grazing and convert it into K2 in their own bodies; humans get the majority of their K2 by consuming animal by-products.
Times have changed, unfortunately. With our new modern farming techniques, most domesticated animals are now kept in barns and fed grains instead of grass. By not consuming grass, the animals are not getting the vitamin K1 that they would normally use to provide vitamin K2 rich by-products. By being housed inside, they no longer get vitamin D exposure from sunlight. While vitamin D is often fortified into animal-feed or added back into milk for human use, vitamin K is not.
Research indicates that K2 may prevent some of the negative consequences of high calcium intake. K2 ensures that calcium intake actually gets into the bone rather than being left to build up in the arteries and soft tissues. Calcium in the bone helps to increase bone density. Calcium in the blood becomes the primary mineral contained in plaque deposits that harden in the arteries, leading to cardiovascular disease. Cardiovascular disease is linked to one-third of human deaths.4
Vitamin K1 is a related form of vitamin K found in leafy green vegetables. It is not significantly involved in bone or cardiovascular health. It does play a role in the blood-clotting factor of blood. Unlike vitamin K2, vitamin K1 is rarely deficient in humans. Those taking blood thinning medication need to monitor their consumption of vitamin K1-containing foods.
How does Vitamin K2 work?
To simplify a very complex process, Vitamin K2 is a protein activator. Its presence activates the proteins MGP (Matrix GLA Protein) and osteocalcin. Calcium binds to these two proteins when they are activated. Activated MGP draws calcium out of soft tissues, organs and arteries. Activated osteocalcin assists calcium in sticking to the bones. These dual actions are what make vitamin K2 so mutually effective for bone and cardiovascular health.
Sources of Vitamin K2
There are two main sources of vitamin K2 commonly available as supplements, MK-4 and MK-7. Both are found in animal by-products; however, MK-4 is only available as a synthetic source for supplementation. MK-7 is available as a natural source supplement. The fermentation of soybeans with the bacteria Bacillus subtilis to create the traditional Japanese dish natto bean, produces a rich, natural source of MK-7 form vitamin K2.
Although vitamin K2 does not get the attention it deserves, the clinical evidence of its effectiveness is well-documented.
Clinical Evidence for Bone Health:
- One study found that Japanese women from areas where natto bean (fermented soy bean) is regularly consumed have a higher concentration of MK-7(vitamin K2) levels than women in areas where natto is rarely eaten. Further, the Japanese women in the natto-eating regions have a reduced risk of bone fracture. A similar study also concluded that osteocalcin, a substance that attracts calcium to the bone, is found in higher concentrations in individuals eating natto on a regular basis.6
- A three-year study completed in 2013, evaluated menopausal women taking 180 mcg daily supplementation of MK-7 form vitamin K2. The study showed that vitamin K2 levels were effectively increased and concluded that MK-7 helped to reduce the loss of bone mineral density and content, while increasing bone strength.7
- A three-year, double-blind study of Vitamin K2 supplementation showed that women taking vitamin K2 had increased bone mineral content.8
Clinical Evidence for Cardiovascular Health:
- A large study in the Netherlands, involving almost 5,000 patients over a ten year period, suggested that consumption of foods rich in vitamin K2 could reduce the risk of arterial calcification and cardiovascular disease by as much as 50%.9
- Another Dutch study done in 2009 concluded that patients with higher dietary K2 levels had a reduced rate of coronary calcification. After 8 years, incidence of coronary heart disease was reduced by 9% for every 10 mcg of vitamin K2 consumption. Researchers commented that the MK-7 form of vitamin K2 could play an important role in reducing cardiovascular disease.10
- MK-7 supplements were shown to improve arterial stiffness in menopausal women in a double-blind placebo study. Women with a higher degree of stiffness benefited the most.11
Health First® Vitamin K2 Max
- Potent dose: Vitamin K2 Max meets Health Canada’s highest allowable daily dose of Vitamin K2 at 120 mcg per dose.
- Superior fermented form: Contains the preferred form of K2, MK-7 (menaquinone-7) from natural natto beans. Natto beans are soybeans that have been fermented with the bacteria Bacillus subtilis, producing nature’s richest source of vitamin K2. This form of K2 is more absorbable and longer-lasting than synthetic forms.
- Osteoporosis Canada. www.osteoporosis.ca
- Hope, Jenny. Calcium pills taken by hundreds of thousands of women ‘double risk of heart attack and could do more harm than good’. May 22, 2012, Daily Mail. http://www.dailymail.co.uk/news/article-2149031/Calcium-booster-pills-raise-risk-heart-attack-harmgood.html#ixzz21nlFlR5S
- J. Bolland, A. Grey, A. Avenell, G. D. Gamble, I. R. Reid. Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women’s Health Initiative limited access dataset and meta-analysis. BMJ, 2011; 342 (apr19 1): d2040 DOI
- Vitamin K2 Shown to Reduce CVD Risk. www.vitamink2.org. International Health and Science Foundation.
- Sato et al., “Comparison of Menaquinone-4 and Menaquinone-7 bioavailability in healthy women.” Nutritional Journal 2012
- Kaneki, M. et al. Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2: possible implications for hip-fracture risk. Nutrition. 2001 Apr;17(4):315-21.
- Knapen, MH 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. doi: 10.1007/s00198-013-2325-6. Epub 2013 Mar 23.
- Tsukamoto Y et al. Intake of fermented soybean (natto) increases circulating vitamin K2 (menaquinone-7) and gamma-carboxylated osteocalcin concentration in normal individuals. J Bone Miner Metab. 2000;18(4):216-22.
- Geleijnse JM et al. Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. J Nutr. 2004 Nov;134(11):3100-5.]
- Gast, GC et al. A high menaquinone intake reduces the incidence of coronary heart disease. Nutr Metab Cardiovasc Dis. 2009 Sep;19(7):504-10. doi:10.1016/j.numecd.2008.10.004. Epub 2009 Jan 28.
- Knapen et al. Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomized clinical trial. Thromb Haemost. 2015 May;113(5):1135- 44. doi: 10.1160/TH14-08-0675. Epub 2015 Feb 19.
- Health Canada. Natural Health Products Directorate. “Multi-Vitamin/Mineral Supplements” monograph.