 For cardiovascular health, this is one of the best things you can do. Jan, connect the dots. Why is magnesium so important for our hearts? Jay, again, it goes to that concept that calcium constricts, magnesium relaxes. We can't, because our diet is usually a little too rich with calcium-related type foods, and we don't get that magnesium. If we don't have that ability for our blood vessels to relax properly,