We are obsessed with magnesium as a dietary supplement. Its “overdose” has a name: hypermagnesemia

Magnesium is increasingly popular as a supplement, but taking it without medical guidance can push blood levels above normal and cause hypermagnesemia.

Early effects are often digestive, followed by neuromuscular symptoms; severe cases can lead to dangerous heart problems and arrhythmias.

The kidneys usually prevent magnesium buildup, but that protection weakens when renal function is impaired.

The warning is especially important for people using magnesium supplements or magnesium-containing laxatives without a confirmed deficiency.