Magnesium and restless legs – any connection?

Restless legs is a condition that affects about 10 % of the British population. It is a disease in the nervous system which results in an uncontrollable urge to move the legs. It is often followed by muscular tensions and a tingling sensation in the legs; a feeling that may be accompanied by pain and/or a different uncomfortable feeling in the leg muscles. The symptoms are usually worse when you are inactive – especially in the evening when you go to bed. As a result, the condition frequently causes poor sleep and sleep deprivation.

Magnesium is a mineral which our body needs to function properly. Some of its functions include regulating different biochemical reactions in the body – i.e. the regulation of the nerve and muscle function - as well as the maintenance of a healthy immune defence. A magnesium deficiency can cause problems with the impulse conduction of the nerves, the muscles ability to contract and possibly result in muscle cramps.

Why does magnesium deficiency contribute to restless legs?

Several studies have suggested that the deficiency can be the cause of some cases of restless legs. In these instances, a supplementation of magnesium can be used to treat the symptoms of restless legs and cure the patient. Therefore, magnesium is currently used to treat restless legs if it is suspected that a magnesium deficiency is the cause of the disease.

Researchers believe that the connection between restless legs and magnesium deficiency is because magnesium helps the muscles relax. To fully understand this, it is necessary to have a little bit of knowledge of muscles and nerves. Without sufficient amounts of magnesium, the nerve paths will become overactive. In a nerve cell, a current flows through, which eventually reaches the end of the long nerve, where the current is transmitted to the next nerve cell or muscle cell. To transmit the signal, calcium needs to enter the nerve cell and report that neurotransmitters (signalling molecules) must be released from the nerve cell, so that molecules can stimulate the next cell.

Magnesium has the ability to prevent calcium from entering the nerve cell by blocking the calcium channel. This mechanism is important, because if there is no magnesium to prevent the calcium from entering the nerve cell, there will be a continuous flow of calcium into the nerve cell. This will make the nerve cell overactive.

Regardless of whether the nerve cell has been instructed to direct current and to signal other cells or not, the nerve cell will release signalling molecules continuously in this situation, because of the calcium constantly entering. It will therefore stimulate a muscle cell over and over, which can result in the feeling of restless legs.

What does research show about magnesium deficiency?

A study has shown that magnesium supplementation to patients with restless legs can relieve sleeplessness, while a different study has shown that it can reduce the feeling of restlessness as well. It is, however, important to remember that this effect may only exist in patients with magnesium deficiency. Magnesium supplementation can have certain side-effects, and it is therefore recommended that you only take the supplement if you are in deficit.

The most common side effects are irritation of the stomach, nausea, vomiting, diarrhoea and stomach cramps. By reducing the dosage, you can reduce the risk of these side effects. High doses of magnesium can be harmful to your health as a great surplus of magnesium in the blood can result in lowered blood pressure, confusion, irregular heartbeat and reduced frequency of breathing. At worst case, it can put you in a coma. If you suffer from haemophilia or a kidney disease, it is advised to completely stop taking magnesium before consulting your GP.

How and how much?

Usually, the recommendation for an adult is about 300 mg, which is considered a safe dosage. You can contact your GP for advice about what dosage you should take. You can also eat more vegetables, which have a greater content of magnesium – i.e. spinach, cabbage, nuts, seeds, fish such as mackerel and tuna, beans, lentils, avocados, bananas and fat free dairy products.

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