Muscle and Bone HealthSuper StrengthMineral SupplementHelps Maintain Healthy Blood Pressure and Glucose LevelsScience-Backed Quality Since 1969 Essential for strong muscles and bones, cardiovascular health and more.  Are you getting enough magnesium in your diet? If not, don’t worry, because we’ve got Swanson Super-Strength Magnesium Citrate. What is magnesium? Magnesium is an essential mineral and can be found in abundance in seeds, whole grains, dark green leafy vegetables and some types of fish. Magnesium is important because it plays a key role in the basic cellular function of the heart and nervous system, offering cardiovascular support and promoting healthy blood pressure levels. Magnesium is also the catalyst for enzyme reactions that create energy.