Effect of Menaquinone-7 (vitamin K2) on vascular elasticity in healthy subjects: results from a one-year study

Background: Matrix Gla-Protein (MGP) is involved in the prevention of arterial calcification. During vitamin K-insufficiency, MGP is produced in its inactive form: dp-ucMGP. Two 3-year intervention studies in the general population have shown that increased vitamin K intake may decrease arterial stiffening, but the difference with placebo became only significant in the third year of treatment. In the present trial we have investigated whether in a pre-selected group of vitamin K-insufficient subjects (men and women) an effect of vitamin K-supplementation may be demonstrated within one year. Methods: A randomized placebo-controlled clinical trial was performed in 243 subjects (40-70 years old) characterized by circulating dp-ucMGP concentrations above the median of the general population. Arterial stiffness was concluded from the carotid-femoral pulse-wave velocity (cfPWV), and other vascular characteristics were measured by echotracking of the common carotid artery. Treatment was performed with either vitamin K (menaquinone-7, MK-7) or placebo for one year. Results: In the total study group, MK-7 induced a significant decrease of both dp-ucMGP and cfPWV. After subdividing by gender, it appeared that the effects were only seen in women, in whom we also found beneficial effects in other vascular characteristics as well as in body weight and BMI. Conclusions : High vitamin K intake decreased age-related vascular stiffening. The effects were most obvious in women with poor vitamin K status and were statistically significant after one year of treatment. In-tima-Media Young’s Modulus