“Magnesium Basics”, 2012 (; backlinks; similar):
Magnesium, as a cofactor in numerous enzymatic reactions, fulfills various intracellular physiological functions. Thus, imbalance in magnesium status—primarily hypomagnesemia as it is seen more often than hypermagnesemia—might result in unwanted neuromuscular, cardiac, or nervous disorders.
Measuring total serum magnesium is a feasible and affordable way to monitor changes in magnesium status, although it does not necessarily reflect total body magnesium content.
The following review focuses on the natural occurrence of magnesium and its physiological function. The absorption and excretion of magnesium, as well as hypomagnesemia and hypermagnesemia, will be addressed.