Magnesium During Pregnancy


Magnesium is the fourth most common mineral in the human body, after calcium, potassium, and sodium. However, unlike other minerals, the importance of magnesium is frequently overlooked. Magnesium is crucial for regulating important biochemical balances in the body, like making proteins and adenosine triphosphate (ATP). ATP is the molecule that provides energy to our cells, but it requires magnesium to be biologically active. Magnesium also plays a vital role in maintaining the health of bones, the nervous system, and the heart,1 while magnesium deficiency is often associated with conditions like high blood pressure, diabetes, and cardiovascular disease.2

During pregnancy, the need for magnesium increases. Magnesium deficiency in pregnant women can endanger both the mother and the infant, especially during the foetal development stage. These health problems for the newborn can continue to have a major impact on adulthood.1 This article will discuss the benefits of magnesium during pregnancy for both the mother and the baby.

Is it safe to take magnesium during pregnancy?

Why do you need magnesium during pregnancy?

A study suggests that while magnesium deficiency can affect most adults, pregnant women are at higher risk. Pregnant women often require more magnesium to meet the demands of foetal development.3 

In addition, magnesium deficiency during pregnancy may be associated with severe complications such as:4

  • preterm birth 
  • preeclampsia (high blood pressure developed during pregnancy) 
  • gestational diabetes (high blood sugar developed during pregnancy) 
  • foetal growth restriction 
  • leg cramps

As mentioned previously, magnesium deficiency can cause serious harm to both the mother and the foetus, therefore, it is safe to take magnesium during pregnancy as long as it does not exceed the daily recommended intake of 360-400mg. 

The above consequences of magnesium deficiency during pregnancy are discussed in more detail below: 

Preterm birth

Preterm birth (birth before 37 weeks of pregnancy) is the leading cause of infant mortality and morbidity. Preterm birth is associated with many long-term complications in survivors, including cerebral palsy, delayed development, and impaired vision and hearing.

Magnesium deficiency has been linked to blood vessel issues, which are often seen in people AFAB who deliver preterm. However, the risk of preterm birth was noted to be lower in people AFAB who took magnesium supplements during pregnancy.5 As a result, pregnant people AFAB are advised to consume foods high in magnesium, such as whole grains and nuts, to prevent magnesium deficiency.


Preeclampsia is a disorder that affects some women after 20 weeks of pregnancy, and it is a leading cause of maternal and infant death. Signs of preeclampsia include hypertension (high blood pressure) and proteinuria (protein in the urine, which could indicate poor kidney function).4 

Doctors and  WHO recommend magnesium sulphate as an initial treatment for preeclampsia, with studies highlighting that it is effective in managing the condition due to its blood pressure-lowering effect.4,6

Gestational diabetes

Gestational diabetes is high blood sugar that develops during pregnancy, affecting women who did not have diabetes beforehand.7 Gestational diabetes reportedly affects 1%-14% of pregnant people AFAB and is linked to an increased risk of preeclampsia and delivery by caesarean section.

Magnesium is important for regulating blood sugar levels, as it improves the activity of insulin (a hormone that helps our cells take sugar out of blood). In addition, a clinical trial highlighted that pregnant women experienced a drop in blood sugar after starting magnesium supplements.7

Foetal growth restriction

A magnesium deficiency during pregnancy may interfere with infant growth and development and result in premature birth. In a recent clinical trial, magnesium supplementation was found to reduce growth restriction, improving the weight of newborns. It also reduced the rate of preeclampsia, which can also cause restricted growth by limiting blood flow to the foetus.8

Leg Cramps

Leg cramps are involuntary, painful spasms that most commonly affect the calf muscles. They affect up to 30% of pregnant people assigned female at birth. Because magnesium has a role in muscle relaxation, magnesium supplementation has been studied as a safe and effective treatment for leg cramps during pregnancy.4

It is clear that magnesium deficiency during pregnancy can cause health complications, so pregnant people AFAB need to get a sufficient magnesium intake through diet or magnesium supplements. It is advisable to consult with a healthcare professional before taking supplements, as they could interfere with certain medications. 

How much magnesium do you need during pregnancy?

According to the National Institutes of Health, the recommended dietary allowance (RDA) for magnesium is 350-400 mg (depending on age) for pregnant female AFAB compared to 310-360 mg for non-pregnant women. As previously discussed, the increase is due to the needs of the foetus and changes happening in the body during pregnancy. Similarly, during lactation, mothers are required to consume 310-360 mg a day.

Table 1: RDA for magnesium during pregnancy and lactation 

14- 18years360 mg400 mg360 mg
19-30 years310 mg350 mg310 mg
30-50 years320 mg360 mg320 mg

However, abnormal magnesium levels can be life threatening. Therefore, it is important to get a blood test if you experience any symptoms such as nausea, muscle weakness/cramps, or cardiac arrhythmia (abnormal heartbeat). 

Best foods with magnesium for pregnant females AFAB

Fortunately, there are many foods that are a great source of magnesium and can offer many health benefits for females AFAB during their pregnancy.

Here is a list of the best foods with a high magnesium content:

Fruits and vegetables

Potatoes, avocados, corn, carrots, and broccoli are great sources of nutrients and contain a moderate amount of magnesium. However, green leafy vegetables, like spinach, contain much more magnesium, with 5 mg per serving. Fruits such as apples and bananas can contain 10-32 mg of magnesium.

Dairy products 

Dairy products such as milk and yoghurt are also good sources of magnesium, containing 27-42 mg. Dairy alternatives like soy milk contain 61 mg per serving.

Seeds and Nuts 

Almonds, peanuts, and cashews are great magnesium sources, containing 60-80 mg of magnesium. Pumpkin seeds and chia seeds are even better, containing 110-156 mg of magnesium.


Soybeans (edamame), black beans, and kidney beans offer 35-60 mg of magnesium. 

Fish, chicken, & beef 

Fish like salmon and halibut contain 26 mg of magnesium. Chicken and lean beef contain 20-22 mg of magnesium.

Whole grains 

Brown rice, oatmeal, raisins, and cereals are great sources of magnesium, having 23-42 mg per serving. White rice has a lower content but is still a magnesium source, containing 10 mg per serving. 


Magnesium is  a vital nutrient in the human body, although its importance is often neglected. Magnesium plays a role in regulating biochemical processes in your body, including normal functioning of the nervous system and heart. 

During pregnancy, the need for magnesium increases to meet the requirements of the foetus and balance out the changes that occur in the body. Magnesium deficiency during pregnancy can put both the mother and the infant at risk of severe health complications, such as preterm birth, preeclampsia, and foetal growth restriction. 

Therefore, to prevent these health risks, pregnant women are advised to follow a balanced diet with a good magnesium intake. Adding magnesium into your diet is safe and can prevent many health problems. Taking a magnesium supplement is also beneficial, although it is best to take it under medical supervision in case of any complications. 


  1. Fanni D, Gerosa C, Nurchi VM, Manchia M, Saba L, Coghe F, et al. The role of magnesium in pregnancy and in fetal programming of adult diseases. Biol Trace Elem Res [Internet]. 2021 Oct [cited 2023 Jan 18];199(10):3647–57. Available from:
  2. Ismail AA, Ismail NA. Magnesium: a mineral essential for health yet generally underestimated or even ignored. J Nutr Food Sci [Internet]. 2016 [cited 2023 Jan 18];6(4). Available from: 
  3. Orlova S, Dikke G, Pickering G, Yaltseva N, Konchits S, Starostin K, et al. Risk factors and comorbidities associated with magnesium deficiency in pregnant women and women with hormone-related conditions: analysis of a large real-world dataset. BMC Pregnancy Childbirth [Internet]. 2021 Dec [cited 2023 Jan 18];21(1):76. Available from:
  4. Dalton LM, Ní Fhloinn DM, Gaydadzhieva GT, Mazurkiewicz OM, Leeson H, Wright CP. Magnesium in pregnancy. Nutr Rev [Internet]. 2016 Sep [cited 2023 Jan 18];74(9):549–57. Available from:
  5. Zhang Y, Xun P, Chen C, Lu L, Shechter M, Rosanoff A, et al. Magnesium levels in relation to rates of preterm birth: a systematic review and meta-analysis of ecological, observational, and interventional studies. Nutrition Reviews [Internet]. 2021 Jan 9 [cited 2023 Jan 19];79(2):188–99. Available from: 
  6. De Sousa Rocha V, Della Rosa FB, Ruano R, Zugaib M, Colli C. Association between magnesium status, oxidative stress and inflammation in preeclampsia: A case–control study. Clinical Nutrition [Internet]. 2015 Dec [cited 2023 Jan 19];34(6):1166–71. Available from: 
  7. Zhang K. Case report: Magnesium—A new therapeutic target in gestational diabetes mellitus? Clin Case Rep [Internet]. 2020 Dec [cited 2023 Jan 19];8(12):2856–8. Available from:
  8. Zarean E, Tarjan A. Effect of magnesium supplement on pregnancy outcomes: a randomized control trial. Adv Biomed Res [Internet]. 2017 [cited 2023 Jan 19];6(1):109. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Aisha Mohamed

BSc (Hons) Nursing Studies (Adult), Nursing, Glasgow Caledonian University

Aisha Mohamed is a Registered Nurse (RN) with a Bachelor of Science degree in Nursing. With a strong academic background, Aisha has developed a comprehensive understanding of the medical field and has a deep commitment to providing quality patient care. Aisha currently works in clinical research specialty as she is passionate about improving community health through scientific medical research. These skills translate to her writing, as she is able to convey important medical information in a way that is easy for readers to understand.

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