Refer a Friend and Earn Offers! - Beli Prenatals are HSA/FSA eligible!

Why Magnesium Is Key For Pregnancy (and not just for sleep!)

Magnesium has enjoyed recent fame as a potential sleep aid and for muscle recovery, but this essential mineral plays a key role in all sorts of bodily functions. During pregnancy, magnesium is even more important—and that’s true for you and your growing baby. Not only is it used by almost every system in your body, adequate amounts of magnesium during pregnancy can help stave off complications like preterm labor (1). In this ingredient spotlight, we’re running down all the facts about magnesium and why it’s such an important ingredient in your prenatal vitamin.

Key Takeaways

  • Magnesium is an essential nutrient, especially during pregnancy, when your need for it increases.
  • Low magnesium levels during pregnancy are associated with higher health risks for mamas and babies alike.
  • Sufficient magnesium levels during pregnancy have a number of benefits, including minimizing leg cramps, promoting sleep, supporting healthy bone development, and assisting hydration.
  • Women need 350 milligrams of magnesium during pregnancy and if they’re breastfeeding.
  • Magnesium also plays an important role during preconception and postpartum.

Magnesium During Pregnancy

Some 300 reactions (2) in the body depend on magnesium to do their thing—we’re talking bone formation, DNA, blood pressure management, blood sugar control, the creation of proteins, muscle and nerve function, and the list goes on. When you’re pregnant, your need for this mineral only goes up and your diet may not be sufficiently keeping up with this increased demand. In fact, roughly 79% of pregnant women are magnesium deficient (3).

That sets up a few potential issues. According to the authors of a 2021 study (4) on the role of magnesium during pregnancy, “Magnesium deficiency during pregnancy is associated with a higher health risk for both mother and newborn, including restricted fetal growth, intrauterine growth restriction, gestational diabetes, preterm labor, and pre-eclampsia.” And that’s not all. Low magnesium during pregnancy can also set the stage for health issues later in life: “magnesium may enter as a main actor in the ‘fetal origin’ hypothesis of multiple human diseases, including the predisposition to develop a metabolic syndrome in childhood or adulthood.”

Sufficient amounts of magnesium, on the other hand, not only minimizes these risks, it also offers additional benefits. 

  • Supports healthy bones. Moms and babies alike need magnesium for healthy bone structure development. 
  • Minimizes cramping. Leg cramps can be common (and awful) during pregnancy. Some research (5) suggests that magnesium can help reduce frequency and intensity of pregnancy-induced leg cramps. 
  • Assists hydration. Staying properly hydrated is extra important during pregnancy, and magnesium acts as an electrolyte. It plays nicely with minerals like sodium and potassium to promote and support hydration. If you’re familiar with the concept of hydrating “better,” this is it! 
  • Improves sleep. Remember the whole sleep aid thing? Magnesium does indeed support more restful sleep, which you’ll really appreciate in the latter stages of pregnancy and getting comfortable enough to nod off is a challenge. 
  • Boosts mood. Magnesium can influence the brain functions (6) that manage stress and anxiety, which makes it particularly valuable for supporting mental health during and after pregnancy. Actually, low magnesium levels are linked to depression.

How Much Magnesium Do You Need During Pregnancy?

According to the NIH, pregnant and breastfeeding women between 31 and 50 need 350 milligrams of magnesium every day. Fortunately, it’s readily available in foods like whole grains, leafy green veggies, certain legumes and fish, seeds like pumpkin and chia, and fruits like avocados and bananas. To fill the gap between what you eat and the nutrients you need to help support a healthy pregnancy, take Beli! 

Our prenatal vitamin is formulated with 100 milligrams of magnesium to supplement a healthy diet, ensuring that you’re getting the vitamins, minerals and antioxidants you need from preconception to pregnancy to postpartum and beyond. In fact, Beli for Women is one of very few formulas on the market meeting current recommendations (7) not only for magnesium, but also for choline, folate, iodine and vitamin D.

Magnesium Before & After Pregnancy

Magnesium deficiencies aren’t just an issue during pregnancy. While conclusive research is still scarce, there is reason to suspect that low magnesium levels could negatively impact the production and health of sperm, since it’s a vital mineral for spermatogenesis. In women, magnesium deficiency is associated with chronic inflammatory stress. That can have a negative impact on hormones and healthy ovulation. Plus, oxidative stress itself can be directly damaging to egg quality.

The benefits of sufficient amounts of magnesium in your diet continue after your baby is in your arms, too, for many of the same reasons. If you’re breastfeeding (and even if you aren’t), you’ll need the electrolytes to maintain proper hydration and fluid balance. Staying hydrated is also critical to support the healing process, maintain energy levels, and boost mood—all of which are particularly important after the baby comes.

Magnesium can also help relieve muscle tension, ease aches and pains following delivery and improve sleep quality (even if it’s coming in limited amounts!) by lowering key stress hormones.

The Bottom Line

Magnesium shouldn’t be overlooked, especially not while you’re pregnant, trying to conceive, or doing your very best to make it through that wild newborn stage. This is a time of life when your needs for this essential mineral are the greatest. While your diet can—and should!—be your primary source of magnesium, a prenatal vitamin with magnesium is an excellent supplement. Fortunately, Beli for Women has you covered.


Han S et al. (2013). Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour.

Magnesium: Fact sheet for health professionals. (2022).

Orlova S et al. (2021). Risk factors and comorbidities associated with magnesium deficiency in pregnant women and women with hormone-related conditions: analysis of a large real-world dataset.

Fanni D et al. (2021). The role of magnesium in pregnancy and in fetal programming of adult diseases. deficiency during pregnancy is,labor%2C and pre%2Declampsia

Supakitisant C et al. (2012). Oral magnesium for relief in pregnancy-induced leg cramps: a randomised controlled trial.

Cuciureanu M et al. (2011). Magnesium and stress.

Nutrition During Pregnancy. (2023).


Any statement made on has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. We recommend consulting with your medical provider before starting any new supplement.

This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Beli.

Additional Resources