Nocturnal cramps: the role of magnesium and potassium

Nocturnal cramps are common

Nocturnal or resting leg cramps are frequent in many older individuals. Even if they can occur at any age, they tend to be more common and more severe in later life. In one study of people over the age of 60 years, almost one-third said that they had had leg cramps within the previous two months. Cramps may also be more common in women. As is known to anyone who suffers from cramps, they are distressful since they cause pain, and may also lead to problems in sleep:

• sleep disturbance;
• poor sleep quality;
• daytime somnolence.

Nocturnal cramps may thus have a significant impact on the overall quality of life and may be a cause of concern, especially in older people.

What causes nocturnal cramps?

Nocturnal cramps are due to sudden, unwanted, and painful contractions of muscles often involving muscles in the calves or feet. In many cases a definite cause for cannot be identified. However, a number of factors have been associated with nocturnal cramps. One such factor is certain medications. Other possible causes of nocturnal cramps include some neurological conditions, while about two-thirds of people with diabetes suffer from cramps. Lastly, muscle cramps may be related associated with alterations in fluids and electrolytes among which magnesium and potassium.

The role of minerals

Our bodies need a proper balance of minerals to function properly. Muscle cells need minerals like magnesium and potassium to contract and relax. An imbalance or deficiency of these electrolytes can cause problems and lead to muscle cramps. Low levels of any of such minerals can allow the muscle to contract, but prevent it from relaxing. In fact, low levels of magnesium and potassium have been associated with leg cramps.

Magnesium

Magnesium plays an important role in a multitude of metabolic reactions and is needed for muscles to function properly. A deficiency of magnesium can result from some chronic diseases and poor nutrition. Older people are at particular risk of magnesium deficiency because they tend to have more chronic diseases and decreased absorption of magnesium. Electrolyte imbalances may also be due to deficiencies in the diet and sweating, in addition to:

• increased urination;
• diarrhea;
• medication side effects;
• problems with absorption.

Since magnesium deficiency leads to neuronal excitability and enhances neuromuscular transmission, it has been suggested that magnesium may play a beneficial role in nocturnal leg cramps. Indeed, magnesium has become a cornerstone in relieving leg cramps.

Potassium

Potassium primarily comes from dietary sources, such as fruits, vegetables, and nuts. In contrast to other electrolytes, potassium is found primarily inside cells, and only 2% of all potassium in the body is present in extracellular fluids. Thus, even a small decrease in serum potassium may represent a significant decrease in the potassium inside cells. Symptoms of potassium deficiency include:

• muscle weakness;
• fatigue;
• constipation.

A common cause of potassium deficiency is increased excretion due to gastrointestinal disturbances like diarrhea. Low levels of potassium are frequent in people taking diuretics and may also be present in individuals with impaired kidney function or diabetes that is not well controlled. To make sure you get enough potassium, make sure that you eat enough fruits like bananas and oranges as well as vegetables like potatoes and green vegetables.

Conclusion

Nocturnal muscle cramps are common in older individuals. While the underlying cause may not be clear, it may be related to conditions like diabetes and medications used to treat high blood pressure and other conditions. Low levels of magnesium and potassium have been related to muscle cramps, and thus it is important to ensure that adequate levels of these minerals are taken in through a healthy diet. However, in some cases, a supplement with magnesium and potassium can help to relieve muscle cramps and support optimal functioning of muscles.