Does low magnesium lead to muscle cramps?

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    Last Updated: April 23, 2025

    Although low magnesium levels are correlated with higher rates of muscle cramps, particularly during pregnancy and at night, a 2020 meta-analysis found that magnesium supplementation is unlikely to reduce idiopathic nocturnal or exercise-induced muscle cramps. The relationship between magnesium deficiency and muscle cramping remains a topic of debate, and there is conflicting evidence on its effect on pregnancy-associated cramps.

    It’s a widely held belief that imbalances in electrolytes — in particular magnesium — may be involved in the etiology of muscle cramps — sudden involuntary contractions of one or more muscles that lead to sharp pains. However, the theory that muscle cramps are related to electrolyte or water imbalances has been questioned, although some evidence suggests that exercise-associated muscle cramps may have their origin in excessive losses of water and sodium during exercise.[1]

    The idea that low magnesium levels play a role in muscle cramping comes from evidence that reduced magnesium levels are correlated to higher rates of muscle cramping during pregnancy[2][3] and in people who experience leg cramps at night.[4] Severe magnesium deficiency has also been associated with a higher incidence of muscle pain and cramping.[5][6]

    However, a meta-analysis published in 2020 concluded that it is unlikely that magnesium supplementation in any form can reduce idiopathic nocturnal or exercise-induced muscle cramps. The available evidence on a reduction in pregnancy-associated muscle cramps was conflicting.[7]

    Does low magnesium lead to muscle cramps? - Examine