Risks and limits of Magnesium Ernährung

Magnesium is essential, but supplementation carries risks and limits. High doses (typically >350–400 mg/day from supplements) can cause diarrhea, nausea, and abdominal cramps, especially with magnesium citrate or oxide. In kidney disease, dangerous hypermagnesemia may occur, leading to muscle weakness, hypotension, and arrhythmias. Bioavailability varies: magnesium oxide is poorly absorbed, while citrate and glycinate are better. Many consumer tests (e.g., MyBody-X) promote magnesium for sleep, stress, or muscles, but evidence is often mechanistic or based on small studies. Serum magnesium levels poorly reflect cellular status; RBC magnesium is more reliable but not standardized. Interactions with medications (diuretics, proton pump inhibitors, antibiotics) are common. The German Nutrition Society recommends covering needs primarily through diet (whole grains, nuts, legumes). Supplements should only be used for confirmed deficiency or increased needs (athletes, pregnancy) and after medical consultation. Limits include variable absorption, lack of test standardization, and overestimation of benefits due to marketing.