RM Touyz et al. NEJM 2024; 390: 1998-2009. Magnesium Disorders
Magnesium “is present in all cells in all organisms from plants to higher mammals and is indispensable for health and life because it is an essential cofactor for ATP, the cellular source of energy…All ATPase reactions require Mg2+–ATP, including those involved in RNA and DNA functions…Magnesium is involved in the control of neuromuscular function, regulation of cardiac rhythm.”
Key points:
- “Hypomagnesemia is present in 3 to 10% of the general population, but its prevalence is increased among persons with type 2 diabetes and hospitalized patients.”
- “Hypomagnesemia is usually associated with other electrolyte derangements, including hypocalcemia, hypokalemia, and metabolic alkalosis, and refractory hypokalemia” (& refractory hypocalcemia) is often responsive to treatment only after the magnesium concentration has been normalized.
- “Patients with hypomagnesemia often present with nonspecific symptoms, such as lethargy, muscle cramps, or muscle weakness, and thus the diagnosis of magnesium deficiency may be overlooked.”
- “Many drug classes, such as antibiotics, diuretics, biologic agents, immunosuppressants (including tacrolimus and rapamycin), proton-pump inhibitors, and chemotherapies, cause renal magnesium loss and hypomagnesemia.”
- “Long-term use of PPIs causes magnesium deficiency in approximately 20% of patients receiving them, and these effects are dose-dependent. PPIs reduce intestinal magnesium uptake.”
- “Dietary sources rich in magnesium include cereals, beans, nuts, and green vegetables (magnesium is the central core of chlorophyll). Of the total dietary magnesium consumed, 30 to 40% is absorbed in the intestine.”
- “Magnesium is a key component of bone — 60% of the total magnesium in the body is stored in this compartment.” Adequate magnesium intake can reduce fractures and osteopenia.
- The intestines-bone-kidney axis regulate magnesium. “Hypomagnesemia may result from inadequate dietary intake, increased gastrointestinal loss, reduced renal reabsorption, or redistribution of magnesium from the extracellular to the intracellular space.” Rarely, hypomagnesemia is related to genetic causes.
- Magnesium replacement is the basis for managing hypomagnesemia. “The most effectively absorbed forms are organic salts (magnesium citrate, aspartate, glycinate, gluconate, and lactate) rather than inorganic salts (magnesium chloride, carbonate, and oxide). However, a common side effect of oral magnesium supplementation is diarrhea, which poses a challenge for oral replacement.”
- Intravenous magnesium (magnesium sulfate) is given for more severe deficiency and often therapeutically for torsades de pointes, acute asthma exacerbations, and preeclampsia or eclampsia.
This article is geared to adult medicine. Children less frequently have hypomagnesemia which is likely related to less frequent comorbidities.
My take: In pediatric patients taking PPIs as long-term therapy, checking magnesium levels is important particularly if there are multiple medications which could affect levels and if there are other comorbidities (e.g. renal disease).
Related study: A Stanford, R Rahhal. Gastro Open J. 2015; 1(4): 107-110. doi: 10.17140/GOJ-1-118 Effect of Chronic Proton Pump Inhibitor Use on Serum Magnesium Levels in Pediatric Patients
Key findings: This small retrospective pediatric study included 31 patients with a mean age of 7.8 years with 74 serum Mg levels. Only 2 patients, of adult age, had Mg levels below the normal reference limit of 1.6 mg/dL


Related blog posts:
- Austin Bradford Hill, PPIs and IBD
- Why Observational Studies Are Misleading & PPI Association with Kidney Stones
- PPIs: Good News on Safety
- PPIs: Good News on Safety (Part 2) | gutsandgrowth
- More Good News for PPIs: NO Increased Risk of Dementia
- Deconstructing PPI-Associated Risks with Nearly 8 Billion Data Points and More on COVID-19 GI Symptoms (Video) | gutsandgrowth
- PPI Side Effects: “Dissecting the Evidence” | gutsandgrowth

