[Calcium for the treatment of leg cramps during pregnancy]. Calcium and magnesium status in pregnant women. A comparison between treatment with calcium and vitamin C in pregnant women with leg cramps. The effect of oral magnesium substitution on pregnancy-induced leg cramps.
In an attempt to evaluate the aetiology and therapy of  leg cramps during pregnancy . patients at an antenatal clinic were treated with calcium or a placebo 60 pregnant women underwent a double blind trial with calcium or ascorbic acid ( 1 g twice daily ) as treatment for leg cramps .  There was no significant difference between the two treatment groups with respect to clinical improvement . In 14 out of 60 patients the symptoms were totally abolished and in another 27 patients the symptoms were significantly decreased by the treatment ( irrespective of drug used ) . In 17 patients the symptoms were unaffected while only two patients experienced an increase in frequency of their leg cramps during therapy . Serum total and ionized calcium concentrations , serum total magnesium and albumin concentrations were determined and were not significantly changed throughout therapy in any of the groups . No biochemical differences were found between the different treatment regimens or between those patients relieved or not relieved of their symptoms . Serum magnesium concentrations were at or just below the lower normal limit ( for non pregnant women ) in treated women and pregnant controls OBJECTIVE Our purpose was to determine whether women with pregnancy-related leg cramps would benefit from oral magnesium supplementation . STUDY DESIGN Seventy-three women with pregnancy-related leg cramps were interviewed about their symptoms in a prospect i ve , double-blind , r and omized trial . Initial serum magnesium levels and diurnal magnesium excretion was determined in 50 % of the patients . Oral magnesium or placebo was given for 3 weeks , after which new interviews and laboratory analyses were performed . RESULTS Serum magnesium levels in these patients were at or below the lower reference limit , as is also often the case in healthy pregnant patients . Oral magnesium substitution decreased leg cramp distress ( p < 0.05 compared with the placebo group , p < 0.001 compared with initial complaints ) , but did not significantly increase serum magnesium levels , excess magnesium being excreted as measured by an increase in urinary magnesium levels ( p < 0.002 ) . CONCLUSION Oral magnesium supplementation seems to be a valuable therapeutic tool in the treatment of pregnancy-related leg cramps
BACKGROUND Many women experience leg cramps in pregnancy .
They become more common as pregnancy progresses and are especially troublesome at night .
OBJECTIVES The objective of this review was to assess methods of preventing and treating  leg cramps in pregnancy .