Magnesium is an abundant mineral in the healthy human body, and is found primarily in the bones, soft tissues, and blood. When magnesium is found in the blood stream, its bio-availability is enhanced. The maintenance of healthy magnesium levels is determined by the kidneys, which excrete excess magnesium into the urine. When serum magnesium levels are low, the kidneys compensate by expelling less magnesium into the urine. Thus, healthy kidney function is prerequisite to maintaining normal magnesium levels in the body. In order for the body to assimilate enough of the mineral, it is necessary to maintain a well-balanced diet, replete with high-magnesium foods. These foods include green leafy vegetables such as spinach and broccoli, and nuts such as almonds, cashews, or peanuts.