Does magnesium help with muscle cramps?

Magnesium plays an important role in the body by ensuring the normal muscle- and nervefunction. It is involved, among other things, in the process of muscle contraction and relaxation. Therefore, it is only matural to conclude that taking extra magnesium could have a relaxing effect on muscle cramps. In this article, we will examine in more detail whether this assumption is correct and whether the scientific evidence can back it up.

Causes of muscle cramps

The causes of muscle cramps have not yet been fully understood. Nevertheless, several theories on the subject are being discussed [1,2]. It is important to note that a detailed medical history is always necessary to determine the cause.

The reason behind the myth

The basic idea behind this theory did not come out of nowhere. Magnesium is essential for the normal functioning of muscle cells and influences, among other things, the cell´s energy metabolism and excitability. It is essential for the regulation of muscle contraction and relaxation. If there is a severe magnesium deficiency in the body, muscle cramps, amongst other symptoms, can indeed appear [3,4]. Furthermore, there were early indications of potentially positive effects of magnesium on muscle cramps during pregnancy [4]. Given that magnesium plays a physiological role in muscle relaxation, it stands to reason that taking additional supplements may also have a relaxing effect on existing cramps.

Magnesium in the treatment of muscle cramps

At present, it is widely believed that a magnesium deficiency is often the cause of muscle cramps. Hence taking magnesium supplements might help relieve cramps or even prevent them altogether, right? The current scientific evidence paints a very different picture. Several studies have been carried out in the past to investigate this question, and in most cases no significant improvement in muscle cramps was observed in terms of their intensity, duration or frequency [3,4]. Although earlier studies suggested that magnesium supplements might have a beneficial effect on cramps during pregnancy, subsequent studies have not been able to confirm this benefit conclusively [3,5]. A severe magnesium deficiency should be treated regardless of whether cramps are present, as it can cause various neuromuscular symptoms. However, this does not mean that ordinary calf cramps are caused by a magnesium deficiency. In most cases, taking extra magnesium has no significant effect on elevating the pain [3–5]. In a placebo-controlled study, the number of cramps was reduced in both the magnesium and placebo groups and no significant difference was observed between the two groups. This suggests that the placebo effect may also play a role in the treatment [6].

Conclusion: Does magnesium help with muscle cramps?

In summary, the current scientific evidence does not provide convincing evidence that magnesium supplementation alleviates muscle cramps. In particular, no clinically relevant benefit has been demonstrated for cramps of unknown cause. The situation is similar for exercise-associated cramps. There are too few suitable studies to demonstrate a therapeutic benefit of magnesium in this context. In the case of cramps during pregnancy, however, the evidence remains contradictory and requires further investigation.

If there is an existing magnesium deficiency, supplementing is advisable. However, this should be done regardless of whether muscle cramps are present or not.

The solution

As the cause of muscle cramps remains unclear in most cases there is no known way to prevent them entirely. However, it is certainly possible to take precautions to reduce the risk. Adequate fluid and nutrient intake is fundamentally important for normal bodily function. Whether additional fluid or electrolyte intake prevents cramps, however, depends on the specific situation and has not been proven for all different types of cramps. It is also suspected that muscle fatigue increases muscle excitability [1]. Excessive muscle fatique should therefore be avoided.

Should exercise-related muscle cramps nevertheless occur, some home remedies seem to have a positive effect. These include, amongst other things, pickle juice. Some studies show that this can sometimes relieve exercise-related cramps very quickly. As the effects sometimes occur within a very short time, it stands to reason that this involves a neuromuscular mechanism [1]. Mustard is also frequently recommended as a home remedy for exercise-related cramps. However, there is only purely anecdotal evidence for its effectiveness. This means that whilst the idea of a neural effect is plausible, it has not yet been sufficiently investigated clinically.

References:

[1]	Miller, K. C., McDermott, B. P., Yeargin, S. W., Fiol, A., & Schwellnus, M. P. (2022). An Evidence-Based Review of the Pathophysiology, Treatment, and Prevention of Exercise-Associated Muscle Cramps. Journal of athletic training, 57(1), 5–15.
[2]	Schwellnus MP Cause of Exercise Associated Muscle Cramps (EAMC) — altered neuromuscular control, dehydration or electrolyte depletion? British Journal of Sports Medicine 2009;43:401-408.
[3]	Garrison SR, Korownyk CS, Kolber MR, Allan GM, Musini VM, Sekhon RK, Dugré N. Magnesium for skeletal muscle cramps. Cochrane Database of Systematic Reviews 2020, Issue 9. Art. No.: CD009402.
[4]	Jeroen H. F. de Baaij. Joost G. J. Hoenderop, René J. M. Bindels, Magnesium in Man: Implications for Health and Disease, Physiological Reviews, Jan 2015
[5]	Jing Liu, Guang Song, Ge Zhao, Tao Meng, Effect of Oral magnesium supplementation for relieving leg cramps during pregnancy: A meta-analysis of randomized controlled trials, Taiwanese Journal of Obstetrics and Gynecology, Volume 60, Issue 4, July 2021
[6]	Roguin Maor N, Alperin M, Shturman E, et al. Effect of Magnesium Oxide Supplementation on Nocturnal Leg Cramps: A Randomized Clinical Trial. JAMA Intern Med. 2017;177(5):617–623.