Magnesium Oxide Provides No Relief from Nocturnal Leg Cramps

Nocturnal leg cramps (NLCs) can cause substantial distress and sleep disruption. Quinine is effective for relieving cramps, but its use is discouraged because of potentially serious adverse effects, including thrombocytopenia and arrhythmias. Many patients believe magnesium supplements (usually magnesium citrate) are effective; however, supporting evidence is weak at best. In this trial, researchers in Israel studied the potential benefits of magnesium oxide supplementation, because it results in higher intracellular magnesium levels than does magnesium citrate. They randomized 94 adults (mean age, 65) with ≥4 NLCs during the previous 2 weeks to once-nightly magnesium oxide (865 mg; equivalent to 520 mg of elemental magnesium) or placebo fo…