Magnesium is the fourth most abundant mineral in your body. It’s involved in over 600 cellular reactions, from making DNA to helping your muscles contract. Despite its importance, up to 68% of American adults don’t meet the recommended daily intake. Low magnesium levels have been linked to many negative health outcomes, including weakness, depression, high blood pressure and heart disease. This article explains what magnesium does for your body, its health benefits, how to increase your intake and the consequences of getting too little.