Therefore, it is imperative to examine in a 24-week, randomized, double-blind, placebo-controlled, two-way parallel-group human intervention study, the effect of magnesium on vascular stiffness. Focus will be on carotid-femoral pulse wave velocity (PWV), the gold standard for the evaluation of vascular elasticity, to quantify vascular stiffness. Urinary excretion of magnesium will be used to assess dietary magnesium uptake. Furthermore, time courses of an increased magnesium intake on changes in BP, other markers reflecting vascular function, and plasma biomarkers related to low-grade inflammation and vascular activity will be measured to unravel possible cause-effect relationships.