Magnesium is an important macronutrient, and it is the fourth most abundant positively-charged ion in the body. It is one of the electrolytes that cause muscles to contract, and it helps regulate your nervous system, blood sugar levels, and blood pressure. Your body needs it to complete more than 300 processes involving enzymes and proteins. Sufficient magnesium can usually be obtained through a normal, healthy diet, but low levels of magnesium can lead to serious problems. *Can help with CONSTIPATION.