Magnesium (Mg) is one of the most important cations in the organism, essential for regulating vascular tone, cardiac rhythm, and endothelial functions. In patients with advanced stage chronic kidney disease (CKD) Mg deficit was associated in various studies with vascular calcifications and increased cardiovascular morbidity and mortality. Patients with CKD frequently have hyperparathyroidism, parathormone (PTH) being an important risk factor for vascular calcifications. Increased serum Mg levels inhibit PTH secretion and stimulate left ventricular hypertrophy, while low serum Mg levels stimulate PTH secretion. Correcting Mg de deficiency results in reduced cardiovascular mortality in these patients.