Reviewed by: Adam Killpartrick, DC CNS
Author: Knapen MH, et al.
Reference: Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomized clinical trial. Thrombosis and Haemostasis. 2015 May;113(5):1135-44.
Objective: Investigation of long-term effects of MK-7 (180 µg MenaQ7/day) supplementation on arterial stiffness in a double-blind, placebo-controlled trial.
Design: Healthy postmenopausal women (n=244) received either placebo (n=124) or MK-7 (n=120) for three years. Indices of local carotid stiffness (intima-media thickness IMT, Diameter end-diastole and Distension) were measured by echotracking. Regional aortic stiffness (carotid-femoral and carotid-radial Pulse Wave Velocity, cfPWV and crPWV, respectively) was measured using mechanotransducers. Circulating desphospho-uncarboxylated matrix Gla-protein (dp-ucMGP) as well as acute phase markers Interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP), tumour necrosis factor-? (TNF-?) and markers for endothelial dysfunction Vascular Cell Adhesion Molecule (VCAM), E-selectin, and Advanced Glycation Endproducts (AGEs) were measured. At baseline dp-ucMGP was associated with IMT, Diameter, cfPWV and with the mean z-scores of acute phase markers (APMscore) and of markers for endothelial dysfunction (EDFscore).
Key Results: After three year MK-7 supplementation cfPWV and the Stiffness Index significantly decreased in the total group, whereas distension, compliance, distensibility, Young’s Modulus, and the local carotid PWV (cPWV) improved in women having a baseline Stiffness Index above the median of 10.8. MK-7 decreased dp-ucMGP by 50?% compared to placebo, but did not influence the markers for acute phase and endothelial dysfunction.
Conclusion: Long-term use of MK-7 supplements improves arterial stiffness in healthy postmenopausal women, especially in women having a high arterial stiffness.
Practice Implication: Vitamin K2 has become a staple for people aiming to support bone health by carboxylation of specific bone proteins that play a regulatory role in bone metabolism. However, this study outlines the direct link that vitamin K has on blood vessel integrity and functionality. The form of MK-7 used in this study was Mena Q7, a soy free version of vitamin K2. Based on this latest research as well as the fact that most modern diets severely lack adequate vitamin K2, inclusion of this nutrient into a cardiovascular support protocol should be standard, unless contraindications are present.