New studies show importance of vitamin K for vascular function
One study published in the American Journal of Hypertension looked at data from 66 diabetics (type 2) found that levels of inactive MGP (matrix GLA-protein) were correlated with artery stiffness.
“Our findings form the basis of further investigation into the role of vitamin K supplementation in reducing arterial stiffness in type 2 diabetes,” wrote researchers from the University of Massachusetts Medical School, Corporal Michael J. Crescenz VA Medical Center, the University of Pennsylvania, and VitaK, Maastricht University.
Similar correlations were reported in the journal Nephron for a study with 83 people with chronic kidney disease.
“Vitamin K is required to activate MGP”
Commenting on the findings of the studies, Hogne Vik, chief medical officer with vitamin K2 ingredient supplier NattoPharma, said: “The mechanism of MGP inhibiting arterial calcification has been clearly established in cellular, animal and now human studies. In fact, adequate vitamin K is required to activate MGP. It is widely recognized that vitamin K2 as Menaquinone-7 is the most bioavailable and bioactive form of vitamin K available as a supplement today.
“These new clinical investigations have documented correlations between arterial calcification and high amounts of inactive MGP - both in diabetic patients and in patients with CKD. The good news is that Vitamin K2 – our MenaQ7 brand MK-7 ingredient - is demonstrated to reduce the levels of ‘inactive’ dp-uc-MGP, and that MenaQ7 is documented to reduce arterial stiffness in healthy individuals as well as in kidney patients,” added Vik.
Vitamin K facts
There are two main forms of vitamin K: phylloquinone, also known as phytonadione, (vitamin K1) which is found in green leafy vegetables such as lettuce, broccoli and spinach, and makes up about 90% of the vitamin K in a typical Western diet; and menaquinones (vitamins K2), which make up about 10% of Western vitamin K consumption and can be synthesized in the gut by microflora.
Menaquinones (MK-n: with the n determined by the number of prenyl side chains) can also be found in the diet; MK-4 can be found in animal meat, MK-7, MK-8, and MK-9 are found in fermented food products like cheese, and natto is a rich source of MK-7.
The potential health benefits of the vitamin include cardiovascular and bone health, with some data also supporting a role for prostate health and cognitive benefits.
The wider benefits of vitamin K were also highlighted in a 2009 study by Joyce McCann, PhD, and Bruce Ames, PhD, from Children's Hospital Oakland Research Institute.
The potential heart health benefits of vitamin K are supported by findings from both observational and intervention trials. Data from the European Prospective Investigation into Cancer and Nutrition (EPIC-NL) cohort, published last year in Clinical Nutrition, indicated that increased intakes of long-chain menaquinones (vitamin K2) may reduce the risk of mortality from coronary heart disease (CHD), but no such associations were observed for vitamin K1 (phylloquinone).
Data from a long term intervention study using NattoPharma’s MenaQ7 vitamin K2 indicated that a daily dose of 180 micrograms per day for three years may inhibit age-related stiffening of the artery walls and improve vascular elasticity (Thrombosis and Haemostasis, 2015, Vol. 113, No. 5, pp. 911–1157).
Sources: American Journal of Hypertension
Published online ahead of print, doi: 10.1093/ajh/hpw146
“Inactive Matrix Gla-Protein and Arterial Stiffness in Type 2 Diabetes Mellitus”
Authors: M. Sardana et al.
Published online ahead of print, doi: 10.1159/000453368
“Correlations of Plasma Desphosphorylated Uncarboxylated Matrix Gla Protein with Vascular Calcification and Vascular Stiffness in Chronic Kidney Disease”
Authors: S. Thamratnopkoon et al.