The authors present evidence for a novel, new hypothesis whereby magnesium deficiency (MgD) acts as a genotoxic agent which probably causes numerous, hertofore, unrecognized consequences, even over a short-term, on the physiological, molecular and biochemical machinery of cardiovascular tissues and cells. The end result of these genotoxic effects of MgD probably plays important roles in the etiology and generation of diverse cardiovascular diseases, atherosclerosis, inflammation, and strokes via alterations in the epigenome of cardiovascular tissues and cells. The importance of adequate water-borne and dietary levels of Mg is emphasized.