Painful Leg Cramps: Can Magnesium Help?

Many people wake up during the night due to painful leg cramps, and for most cases, there is no cure yet. Generally speaking, muscle cramps can be caused by excessive use of the muscles, but also due to other causes like dehydration. In many cases, however, the pain is idiopathic, meaning the cause isn’t known, and thus, is no easy feat to cure.

Some forms of muscle cramps are more severe and can have underlying medical causes. These may include inadequate blood supply caused by narrowing of the arteries during exercising and nerve compression due to certain movements causing pain. Another possible cause may be depletion of minerals like potassium, calcium or magnesium in the body, which could be lacking in your diet.

How magnesium can help

Doctors used to prescribe quinine to treat muscle cramps. Today, quinine is forbidden due to its dangerous side effects, such as life threatening blood-disorders, heart rhythm irregularities, or severe allergic responses. Nowadays only certain tonic waters which contain quinine at low concentrations or bananas, which naturally contain quinine, are recommended. Since mineral depletion can be a cause of muscle cramps, magnesium supplementation is seen as a valid option to treat leg cramps because of its usefulness in correcting electrolyte imbalance.

Magnesium is important for muscle functioning, for example, in the heart, but also for bone synthesis and the transfer of nerve stimuli. This means that muscle and nerve dysfunctions, such as cramps, can occur when magnesium is depleted. Additionally, the amount of magnesium from the diet should be high enough. This allows the body to absorb the needed dose. Magnesium can be found in a variety of nutrients, such as fish, nut, whole grains and leafy greens.

Magnesium in the diet and supplementation

Magnesium in supplement form is easier to absorb compared to magnesium directly from food. The magnesium in food first needs to be isolated by digestion, which is a complicated process. On estimation,  only 30 % of magnesium ingested via food is absorbed. The recommended ADI (average daily intake) for magnesium is 280 milligrams for females and 350 milligrams for males. This amount already takes into account the low absorption percentage via food intake. Nevertheless, around 25 % of adults and more than 50 % of teenagers do not consume enough magnesium from their diet.

When the body lacks magnesium, supplementation could be a solution. If a person has lower than normal magnesium levels, the amount taken as a supplement can restore the normal level within tissues. The time necessary for this to happen depends on how low the magnesium level is in an individual, the diet that person follows, and the type of magnesium supplement taken.

Magnesium supplements are available in a variety of compounds. Different compounds can mean the different substances to which they are bound, such as organic compounds (e.g. ascorbic acid), or if they exist in their salt form with other inorganic compounds (e.g. chloride). Keep in mind that organic compounds are easier to absorb compared to inorganic ones. Magnesium oxide is badly absorbed, while magnesium citrate and lactate are readily absorbed.

An important thing to remember is that oversupplementation of magnesium can easily lead to side effects such as diarrhoea. The European Food Safety Association (EFSA) has set the maximum daily magnesium dose via supplementation to 250 milligram per day. Significantly higher doses, around 2500 milligrams, can even lead to muscle weakness and low blood pressure.

Research on magnesium

To date, there are a number of studies on magnesium, but data on its role in relieving leg cramps have contradictory results. A number of these show a potential effect, but some show no effect when compared to the placebo. Differences in these results may be explained by the method and circumstances by which the study was conducted, which are almost never the same.

The problem with current findings is that certain factors can vary greatly between different studies, thus influencing the results. A very clear example is the number of participants, which should be high enough to produce convincing results. When this is not the case, the outcome is not very statistically reliable. These and other parameters may affect the results of such studies and therefore make it difficult to conduct proper research on certain topics.

Research, however, has proven that certain foods and drinks diminish your magnesium resources, allowing leg cramps to occur more often. For instance, carbonated drinks like Coke bind magnesium, rendering it unable to be used by the body. This only means that another way of ensuring that you have enough magnesium is to change your diet.


To sum things up, in theory, magnesium supplementation can potentially help against leg cramps.  Though more accurate studies are needed to establish this, many people have found magnesium supplementation helpful in reducing leg cramps.

So if you’re looking for a way to beat those cramps, you can try upping your magnesium intake. It’s not only good for your muscles and nerves but for overall health as well.