Oral Magnesium for Leg Cramps in Pregnancy

by | Jan 26, 2021 | 2020, Magnesium, Minerals, Pregnancy and Lactation, Women's Health

Written by Jessica Patella, ND. Oral magnesium supplementation of 300mg daily during pregnancy did not reduce the occurrence and frequency of leg cramps episodes.

pregnancy - women's healthLeg cramps are a painful muscle contraction that typically occurs in the calf muscle at night 1,2.  An estimated 30-50% of pregnant women experience leg cramps at least twice a week during the final trimester of pregnancy 1,3.  Because magnesium plays an important role in muscle function and there is an increased need for magnesium during pregnancy, it was tested to determine if it could help decrease leg cramps in pregnant women 1.

Magnesium is an important mineral for metabolism, the nervous system and muscle functioning 1,4.  Magnesium has also been shown to help eclampsia-related seizures in pregnant women 5.  It has also been used traditionally for fetal growth, reducing the risk of preeclampsia, and leg cramps, but randomized trials are limited 1,6.  Magnesium intake is also even more important in low-income areas where insufficient intake is common 1,7.

The research included 132 pregnant women from Brazil, with leg cramps in their first trimester of pregnancy.  They were randomized to receive either magnesium (300 mg/d magnesium citrate; n=66) or a placebo (n=66) for 4-weeks.

At baseline:

  • 56% had 2 leg cramps per week
  • 2% had 3 leg cramps per week
  • 8% had 4 episodes per week
  • 13% had 5 or more episodes per week

After 4- weeks of supplementation there was 28.4% (95%CI: 20.9-37.0) reduction in leg cramps in all participants and no significant difference between the magnesium group and placebo group was observed.  Among women with leg cramps the number of episodes per week also showed no significant difference between the magnesium and placebo groups.  The mean magnesium serum level was 1.84 mg/dL in both the magnesium and placebo groups 1.

In conclusion, the trial did not observe a difference in severity or occurrence of leg cramps in pregnant women when supplementing with magnesium.  Research on magnesium has varied with results and types of magnesium supplemented.  Researchers stated that the study was limited by the fact that the intensity of the leg cramp was not evaluated (although that is still prone to bias).  Also, women were only evaluated in their first trimester of pregnancy, yet leg cramps tend to be most severe in the third trimester of pregnancy and magnesium levels were not assessed after supplementation to determine if magnesium levels were affected by supplementation 1.  Future research should address the limitations to the study, along with sample size 1.

Source: Araújo, Carla Adriane Leal de, Suélem Barros de Lorena, Guilherme Camelo de Sousa Cavalcanti, Gabriel Landim de Souza Leão, Geraldo Padilha Tenório, and João Guilherme B. Alves. “Oral magnesium supplementation for leg cramps in pregnancy—An observational controlled trial.” PloS one 15, no. 1 (2020): e0227497.

© 2020 Arau´jo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Click here to read the full text study.

Posted January 26, 2021.

Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com. http://www.naturalhealthresearch.org/wp-content/uploads/2017/10/jessica-patella-head-shot.jpg

References:

  1. Araújo CAL, Lorena SB, Cavalcanti GCS, Leão GLS, Tenório GP, Alves JGB. Oral magnesium supplementation for leg cramps in pregnancy-An observational controlled trial. PLoS One. 2020;15(1):e0227497.
  2. Zhou K, West HM, Zhang J, Xu L, Li W. Interventions for leg cramps in pregnancy. Cochrane Database Syst Rev. 2015(8):Cd010655.
  3. Ponnapula P, Boberg JS. Lower extremity changes experienced during pregnancy. The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons. 2010;49(5):452-458.
  4. Schwalfenberg GK, Genuis SJ. The Importance of Magnesium in Clinical Healthcare. Scientifica. 2017;2017:4179326.
  5. Ahmed F, Mohammed A. Magnesium: The Forgotten Electrolyte-A Review on Hypomagnesemia. Medical sciences (Basel, Switzerland). 2019;7(4).
  6. Plećas D, Plesinac S, Kontić Vucinić O. Nutrition in pregnancy: basic principles and recommendations. Srpski arhiv za celokupno lekarstvo. 2014;142(1-2):125-130.
  7. Darnton-Hill I, Mkparu UC. Micronutrients in pregnancy in low- and middle-income countries. Nutrients. 2015;7(3):1744-1768.