Serum Magnesium Blood Test - Serum Magnesium Test

This laboratory test measures the concentration of magnesium ions in blood serum. Magnesium is the fourth most abundant cation in the body and plays a central role as a cofactor for more than 300 enzymes, particularly those involved in energy production, muscle contraction, nerve impulse transmission, and bone health. The serum level reflects the balance between dietary intake, intestinal absorption, and renal excretion.