Research continues to strengthen and position vitamin K2 as MK-7 as a substance that protects heart health by helping the body to properly utilise calcium
Healthy ageing has been defined as 'a process of optimising opportunities for physical, social and mental health to enable older people to take part in society without discrimination and to enjoy an independent and good quality of life.'1
The two most significant health issues that can limit us from active, social lifestyles are cardiovascular events and potential fractures from weak, porous bones. The increased risk of developing poor bones and cardiovascular health problems can be a hindrance for the growing population of senior citizens to engage in activities, travel and exercise.
Meanwhile, there is a clinically validated nutrient that delivers true antiageing properties — helping users to keep their bones and arteries healthy as they age. That nutrient is vitamin K2 as MK-7 (menaquinone-7). Recent data from important clinical studies have been published within the last year that not only confirm the cardioprotective benefits of vitamin K2, but also demonstrate that this nutrient can be successfully delivered in formats beyond the traditional supplement tablet or capsule.
K vitamins are a group of fat-soluble vitamins. The two most important forms are vitamin K1 (phylloquinone) and K2 (menaquinone). All K vitamins are needed for proper blood coagulation, whereas vitamin K2 — and not K1 — is essential to build and maintain strong bones, as well as to avoid calcium deposits in the arteries and blood vessels. Vitamin K2 exists in several forms; the commercially available forms are the synthetic menaquinone-4 (MK-4) and the natural or nature-identical synthesised menaquinone-7 (MK-7).
During remodelling, the body releases calcium in the bloodstream to meet its metabolic needs, allowing the bone to alter size and shape as it grows or repairs from smaller injuries.2 Two types of cells regulate remodelling: osteoblasts build up the skeleton, whereas osteoclasts break it down. As long as these two cells types are in balance, a healthy bone structure is maintained.
Osteoblasts also produce osteocalcin, a K-dependent protein that helps to take calcium from the blood circulation and bind it to the bone matrix, making the skeleton stronger and less susceptible to fracture. But newly made osteocalcin is inactive; it needs vitamin K to become fully activated and bind calcium.3
The same process that allows vitamin K2 to support bone health makes it an invaluable nutrient for cardiovascular health. Matrix Gla protein (MGP) is the most potent modulator of arterial calcification known today. It also binds calcium; but, in doing so, it protects blood vessels from calcification, but only when activated, which requires adequate vitamin K2 intakes.4
According to the World Health Organization (WHO), cardiovascular disease (CVD) causes more than half of all deaths across the European region. Yet, WHO asserts that 80% of premature heart disease and stroke is indeed preventable. Population-based studies, such as The Rotterdam Study and the Prospect Study, have suggested and established a link between vitamin K2 intake and cardiovascular health.5,6 Finally, in May 2015, a breakthrough intervention trial with cardiovascular endpoints was published, confirming the association that previous studies had established.7
Researchers at the R&D Group VitaK of Maastricht University in the Netherlands monitored 244 healthy postmenopausal women for 3 years using pulse wave velocity and ultrasound techniques. The participants, aged 55–65 years, were randomly assigned to take a nutritional dose (180µg) of vitamin K2 as MK-7 (as MenaQ7 from NattoPharma) daily for 3 years, or placebo capsules.
After 3 years of supplementation, the Stiffness Index ß in the MenaQ7 group with initial high arterial stiffness had decreased significantly compared with the slight increase in the placebo group (0.67±2.78 vs +0.15±2.51, respectively, p=0.018). Results confirmed that MenaQ7 not only inhibited age-related stiffening of the artery walls, but also made a statistically significant improvement in vascular elasticity — meaning that arteries actually become more flexible (Figure 1).
Healthy men (n=32) and postmenopausal women (n=28) with a mean age of 56 (SD 5) years received either a basic or fortified yoghurt drink twice per day for 12 weeks. MK-7 was efficiently absorbed from the fortified yoghurt drink. Levels of circulating MK-7 were significantly increased from 0.28 to 1.94ng/mL. Intake of the fortified yoghurt drink improved vitamin K status, as measured by significant decreases in inactive osteocalcin and MGP.8
A second study, just published this year in the European Journal of Clinical Nutrition, showed that vitamin K2 as MK-7 was effectively delivered in yoghurt as well as softgel capsules.9 The researchers compared the fasting plasma concentrations of MK-7 from (a) yoghurt enriched with MK-7, vitamins D3 and C, magnesium, n-3 polyunsaturated fatty acids (n-3 PUFA) and fish oil (yoghurt Kplus); (b) yoghurt fortified with MK-7 only (yoghurt K); and (c) softgel capsules containing only MK-7 for 42 days in healthy men and postmenopausal women between 45 and 65 years of age. (The MK-7 in the yoghurts and the capsules was MenaQ7 from NattoPharma ASA.)
Circulating MK-7, 25-hydroxy vitamin D (25(OH)D) and markers for vitamin K status (uncarboxylated or inactive osteocalcin and MGP) were assessed. The results of this 42-day study revealed that the increase in plasma MK-7 with the yoghurt product was more pronounced than the increase in MK-7 with the capsules (Figure 2). However, circulating inactive MGP and inactive osteocalcin levels were significantly lowered after consumption of both the yoghurt products and the MK-7 capsules, reflecting vitamin K status improvement from both delivery methods.
This study adds to the growing body of evidence showing that vitamin K2 as MenaQ7 can be delivered and is highly bioavailable through yoghurt and softgel capsules, making the nutrient safe, effective and available to an even larger population.
The importance of vitamin K2 as MK-7’s role in cardiovascular health extends beyond senior citizens. Vitamin K2 has been well documented for its important role of physiological calcium-metabolism throughout life: we need sufficient K2 to secure healthy cardiovascular foundation during childhood; and we need K2 to keep our arteries clear and flexible during our active, adult life to carry us into our senior years in the best possible health. As most published estimates of vitamin K2 content and intake in diets from Europe, US and Asia conclude that we are not consuming sufficient vitamin K2, supplementation of this important nutrient presents a viable alternative.
1. The Swedish Institute of Public Health, 'Healthy Ageing: A Challenge for Europe 2013,' ISBN: 91-7257-481-X (http://ow.ly/104TPO).
2. R.P. Heaney and C.M. Weaver, 'Newer Perspectives on Calcium Nutrition and Bone Quality,' J. Am. Coll. Nutr. 24(6), 574S–581S (2005).
3. P.V. Hauschka, 'Osteocalcin: The Vitamin K-Dependent Ca2+-Binding Protein of Bone Matrix,' Haemostasis 16(3-4), 258–272 (1986).
4. E. Theuwissen, E. Smit and C. Vermeer, 'The Role of Vitamin K in Soft Tissue Calcification,' Adv. Nutr. 3(2), 166–173 (2012 ).
5. J.M. Geleijnse, et al., 'Dietary Intake of Menaquinone is Associated with a Reduced Risk of Coronary Heart Disease: The Rotterdam Study,' J. Nutr. 134, 3100–3105 (2004).
6. G.C. Gast, et al., 'A High Menaquinone Intake Reduces the Incidence of Coronary Heart Disease,' Nutr. Metab. Cardiovasc. Dis. 19, 504–510 (2009).
7. M.H. Knapen, et al., 'Menaquinone-7 Supplementation Improves Arterial Stiffness in Healthy Postmenopausal Women: Double-Blind Randomised Clinical Trial,' Thrombosis and Haemostasis 113(5), 1135–1144 (2015).
8. H. Marjo, et al., 'Yogurt Drink Fortified with Menaquinone-7 Improves Vitamin K Status in a Healthy Population,' J. Nutr. Sci. 4:e35 (16 October 2015).
9. M.H. Knapen, et al., 'Steady-State Vitamin K2 (Menaquinone-7) Plasma Concentrations After Intake of Dairy Products and Soft Gel Capsules,' doi: 10.1038/ejcn.2016.3 (Epub ahead of print).