At least 30% of all pregnant women get painful muscle cramps in their legs, particularly during the third trimester and most often at night.

Researchers at the Tehran University of Medical Sciences conducted a study to compare the effects of different vitamin supplementation on pregnancy leg cramps. In total, 84 pregnant women were randomly assigned to one of four groups: one received daily calcium carbonate; one received daily magnesium; one received daily vitamin B1 and B6; while the last group was untreated and used as a control. The three treatment groups were then assessed after a period of four weeks.

The researchers reported that in each of the three treatment groups, supplementation had positive effects. In the calcium group, 52% reported “absolute improvement,” meaning the muscle cramps were completely gone by the end of the trial. An additional 43% reported “relative improvement,” where the cramps decreased in frequency and intensity. Only 5% of the women taking calcium carbonate experienced no change in symptoms.

All the women in the magnesium group reported improvements: 71% had “relative improvement” and 29% had “absolute improvement.” The group taking B-vitamins also experienced positive results: 72% reported “absolute improvement” and another 19% reported “relative improvement,” while 9% experienced no change.

Other recommendations for easing leg cramps include drinking plenty of water, daily stretching exercises and using a hot water bottle or heating pad.

Source: Int J Gynecol Obstet Aug 17, 2006