Magnesium is an important mineral involved in over three hundred biochemical processes in the human body.

Magnesium is involved in muscle and nerve function, maintaining proper cardiac rhythm, the formation of bone, in energy metabolism, and protein synthesis.

Magnesium is aborbed through the small intestine. Blood levels are controlled by excreting excess magnesium through the kidneys.

Although generally considered safe, consult your physcian before beginning a regimen of magnesium supplementation. Special caution should be taken by patients with compromised renal function.

Hypomagnesemia (low magnesium levels)
Your doctor may recommend magnesium supplements to prevent or correct hypomagnesemia. Symptoms of hypomagnesemia include: muscle cramps, tingling, abnormal heart rhythms, and if left uncorrected; seizures. Hypomagnesemia is also associated with low levels of other electrolytes: calcium and potassium.

Hypomagnesemia may be caused by:

renal wasting
malabsorption disorders
inadequate dietary intake
Renal Wasting
Kidneys attempt to correct for low magnesium intake by adjusting the amount excreted in the urine. Kidneys can be impaired from regulating magnesium due to a disease state or as a side-effect of medications.
Several drugs are known to deplete magnesium through the urine:

Oncology
Cisplatin
Carboplatin
Oxaliplatin
ErbituxTM(cetuximab)
Some antibiotics
GentamicinTM
AmphortericinTM
Transplantation (Solid Organ or Stem Cell/BMT)
CyclosporinTM
PrografTM (Tacrolimus)
Cardiology
LasixTM
BumexTM
EdecrinTM
Hydrochlorothiazide
Malabsorption Disorders
Crohn's and Colitis patients can experience hypomagnesemia due to inadequate absorption of magnesium through the small intestine.

Inadequate Dietary Intake
The quality of a person's diet may affect the magnesium status. A diet void of leafy green vegetables, nuts, whole grains, etc. may be the etiology of magnesium deficiency. Dietary surveys vary greatly on the severity of this condition for most Americans. Low magnesium levels are also associated with alcoholism or poorly controlled diabetes.