Proton Pump Inhibitors and Severe Hypomagnesaemia

Tim Cundy; Jonathan Mackay


Curr Opin Gastroenterol. 2011;27(2):180-185. 

In This Article

Biochemical Tests Available

Measurements of plasma ionized or total magnesium (or red cell magnesium) are the most readily available methods for determining magnesium status, but they may not necessarily represent whole body stores. Urinary magnesium can be measured on timed collections – generally reflecting the current intake of magnesium – or as a fractional clearance relative to creatinine clearance (C Mg/C creatinine), which assesses renal magnesium handling. A more rigorous assessment of the latter can be made through a stepwise incremental magnesium infusion from which the TmMg can be estimated (normal >0.6 mmol/l). The whole body magnesium deficit can be estimated from the percentage of a known magnesium load infused intravenously that appears in the urine over the following 24 h (normal <25% retention). The latter two tests can be combined. There are no simple and reliable tests for assessing magnesium absorption or losses from the intestine.