Magnesium is the fourth most abundant mineral in the body. Magnesium is absorbed from the diet in the upper intestine and excreted in the kidney. The body conserves magnesium by reabsorption by the renal tubules, therefore, in magnesium deficiency urine excretion is extremely low. More than 50% of magnesium in the bone is associated with calcium and phosphorus, the remainder is divided between the muscles and soft tissue. Only 1% of magnesium is found in the blood. Magnesium is the predominate intracellular cation, second only to potassium.
Magnesium is essential for the activation of adenosine triphosphate (ATP) providing cell energy and is an essential co-factor for more than 300 separate enzymes. It is also important for intracellular synthesis of RNA and DNA.
High plasma magnesium is usually due to increases in medicinal intake such as magnesium sulphate therapy, magnesium containing antacids and renal failure. Low plasma magnesium is due either to low intake as in malabsorption or increased loss of magnesium; renal tubular loss, dialysis with low magnesium dialysate, hyperaldosteronism, hyperparathyroidism, diabetes mellitus, alcoholism, diuretic therapy and aminoglycoside therapy.
Low urine magnesium measurement is used to indicate magnesium deficiency as low excretion rates occur when the body magnesium stores are low. Also reduced excretion may occur in severe renal failure.
Increased urine magnesium is seen in generalised renal disease, renal tubular disease, increased production of aldosterone, hyperparathyroidism, diabetes mellitus, intensive diuretic therapy, alcoholism and gentomycin treatment.
Lipids/Trace Metals
UMG
Collect 24 hour urine samples on acid
Aliquot sample for UCRN analysis
Ambient 72 hours, refrigerated (preferred) 14 days, frozen 30 days
14 days
4095