Leg cramps are caused by an involuntary contraction of the muscles and result in a sharp, sudden pain. They occur most often in the calf, but can happen anywhere in the leg. Leg cramps can happen anytime, but they often occur after exercise or at night. Nighttime cramps are the most common and are referred to as nocturnal cramps. While magnesium deficiency can cause cramping, actual magnesium deficiency is rare in the U.S., according to the Office of Dietary Supplements, a branch of the National Institutes of Health. Although some medical professionals say taking magnesium supplements may help leg cramps, studies done on the topic have had mixed results.
Leg Cramp Causes
The causes of leg cramps are not completely understood, but they are not usually the result of an underlying medical disorder. Some things that may cause leg cramps are pregnancy; overuse of your muscles; mineral deficiency; or imbalance, dehydration, certain medications and thyroid disease. Being overly sedentary, wearing ill-fitting shoes and circulatory problems may be a factor as well. The minerals most often associated with cramping are electrolytes, which are electrically charged minerals that participate in movement of muscle. In addition to magnesium, potassium, sodium and calcium are the most common electrolytes associated with leg cramps.
Magnesium Deficiency
Magnesium is the fourth most abundant mineral in the body, according to the ODS. It helps maintain muscle function, supports your immune system, maintains bone structure and keeps your heat beating steadily, as well as many other functions. Deficiency of magnesium can lead to nausea, loss of appetie, fatigue and vomiting in the early stages. As magnesium deficiency gets worse, cramps, muscle contractions, numbness, tingling and seizures can occur. Low levels of magnesium can also decrease the amount of sodium and potassium in the blood. While many Americans don't get enough magnesium in the diet, according to surveys done, true magnesium deficiency is rare.
Studies
Studies of magnesium as an effective treatment for leg cramps have been mixed. A November 1999 study published in "The Journal of Family Practice" found that magnesium was not effective in treating nocturnal leg cramps. But a study published in May 2002 in the "Medical Science Monitor" reported that participants reported a much higher rate in the reduction of cramps when taking magnesium as compared to a group who took a placebo pill, although the researchers did state further study was needed. Women who are pregnant often get leg cramps, particularly at night, but a study published in the May 2008 edition of the "European Journal of Obstetrics, Gynecology and Reproductive Biology" reported that pregnant women treated with 360 mg of magnesium daily reported no significant reduction in leg cramps when compared with a placebo group. However, a study published in 1995 in the July edition of the "American Journal of Obstetrics and Gynecology" found that the exact opposite was true.
Recommendations
Simple steps can be taken to possibly avoid as well as treat leg cramps. When the cramp occurs, flex your foot, toes pointing to the ceiling, and hold that position until the cramping stops. Applying heat and massaging the muscle can help. Stanford University recommends consuming plenty of potassium-rich foods, such as bananas, potatoes, oranges and grapefruit to avoid cramps. If you feel you may be deficient in magnesium, consult your doctor for a diagnosis. He can run tests to check for mineral deficiency. Avoid taking magnesium supplements without first consulting your physician as taking too much magnesium can be harmful, and can possibly lead to further cramping.
References
- Stanford University: Nocturnal Leg Cramps
- Office of Dietary Supplements: Magnesium
- "The Journal of Family Practice"; Magnesium for the Treatment of Nocturnal Leg Cramps: A Crossover Randomized Trial; R. Frusso, et al.; November 1999
- "Medical Science Monitor"; Randomised, Cross-Over, Placebo Controlled Trial of Magnesium Citrate in the Treatment of Chronic, Persistent Leg Cramps; C. Roffe, et al,; May 2002
- "European Journal of Obstetrics, Gynecology and Reproductive Biology"; Does Oral Magnesium Substitution Relieve Pregnancy-Induced Leg Cramps?; I.H. Nygaard, et al.; November 2008
- "American Journal of Obstetrics and Gynecology"; The Effect of Oral Magnesium Substitution on Pregnancy-Induced Leg Cramps; L.O. Dahle, et al.; July 1995
