Is a magnesium deficiency the unlikely culprit behind your leg cramps? Here’s how to know


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Magnesium is one of the most hyped-up natural salves for all types of muscle-related pain—from headaches to digestive distress to menstrual cramps. (One doctor even went so far as to deem it “the miracle mineral for periods.”) So it’s not surprising that some experts believe the mineral can also be a great antidote for leg cramping, whether it’s a Charley horse that wakes you up suddenly at night or a bout of exercise-induced achiness that lingers for days after your sweat sesh.

Here’s the deal: Magnesium plays VIP roles across several different body systems, including muscle and nerve function. It helps shuttle calcium and potassium ions across cell membranes, which is required for healthy nerve impulse conduction and muscle contraction. Given that cramping is, by definition, a series of painful muscle contractions, it makes sense that health pros would consider the role of magnesium deficiency in causing cramps.

Rachel Gargiulo, a certified nutrition consultant, is one expert who’d likely recommend magnesium supplementation if she had a client suffering from frequent leg cramping. “Having a magnesium deficiency is associated with muscle cramps,” she says—a view that’s backed up by science. And Gargiulo isn’t the only one who believes increasing magnesium may prevent recurrent cramps. Dr. Lara Briden, a naturopathic doctor, and Kat Schneider, the CEO and founder of natural supplement brand Ritual, also sing the praises of magnesium and laud its positive effects, especially on the nervous system.

But researchers have a slightly less optimistic perspective on the mineral’s effectiveness for leg cramps, specifically—and it’s worth knowing about before you shell out for a bottle of supplements

Can magnesium really help soothe leg cramps? Here’s what science has to say.

Does magnesium help leg cramps?
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The truth about magnesium’s effectiveness in treating leg cramps

The thing is, there are many causes of leg cramps, and not all of them are linked to magnesium deficiency—for instance, some are a side-effect of medication, while others could indicate vascular disease. In fact, many studies have shown that magnesium is no more effective than a placebo in treating leg cramps, although most of them were done on older adults.

There is, however, some evidence in favor of magnesium’s potential to treat leg cramps in pregnant women. The results of three separate studies were mixed; while two suggested no observed benefits of magnesium supplementation, a third demonstrated a reduction in both frequency and intensity of pregnancy-associated leg cramps in patients who received magnesium supplements when compared to those who received a placebo. Although it’s impossible to draw a definitive conclusion from this limited data, the initial results are encouraging for women who suffer from prenatal leg cramps, which often don’t have a clear cause.

Bottom line? Talk to your doctor about your cramps and ask them whether they think magnesium may help you—they may choose to test your magnesium levels to see if you’re deficient. (Up to 75 percent of people are.) If that’s the case, and your doctor thinks it may be causing your cramps, it may be worth intentionally bolstering your diet with magnesium-rich foods, particularly if you experience any other symptoms of magnesium deficiency, such as depression, anxiety, osteoporosis, fatigue, muscle weakness, high blood pressure, or irregular heartbeat.

Many studies have shown that magnesium is no more effective than a placebo in treating leg cramps, although most of them were done on older adults.

Though magnesium occurs naturally in a range of foods such as green leafy vegetables, legumes, nuts, seeds, whole grains, and even dark chocolate, the body only absorbs 30-40 percent of the dietary magnesium that is consumed. That’s why supplementation is also often recommended. “For prevention of cramps, I’d recommend taking 400mg per day in the form of magnesium glycinate,” says Gargiulo. Both Dr. Briden and Schneider concur with Gargiulo’s suggestion to supplement with magnesium glycinate while steering clear of harsher forms of magnesium, including magnesium oxide, magnesium hydroxide, and magnesium chloride.

If you try oral magnesium supplementation and find it isn’t floating your boat, many physical therapists, coaches, and personal trainers recommend the use of Epsom salts, which are a mineral compound consisting of magnesium and sulfate. You can either apply Epsom salts to a wet cloth and press it against a cramped muscle, or dissolve the salts in a hot bath as a means of alleviating painful cramps.

Magnesium aside, there are a variety of other natural treatments available to assist in managing stubborn cases of cramps—the Mayo Clinic recommends using heat to soothe leg cramps in the moment, and staying hydrated and stretching as preventative measures. And while you’re at it, a serving of magnesium-rich dark chocolate is unlikely to cause any harm. Take that, Charley horse.

If leg cramps are getting you down, you could also try slathering on arnica or snuggling up with a bar of soap while you sleep. (No joke.) 

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