Magnesium is one of the essential minerals your body needs to function properly—and it becomes even more important during pregnancy. It plays a key role in maintaining healthy nerve and muscle activity, supporting bone development, producing energy, and regulating blood sugar and pressure levels.

Pregnant people are more likely to have low magnesium levels, and this can be due to factors like dietary changes or morning sickness. You can increase your intake through magnesium-rich foods like leafy greens, whole grains, legumes, and nuts, or by using supplements if needed. In general, the safe dosage for pregnant individuals is about 350–400 mg per day, depending on age and individual health.

Can Pregnant People Take Magnesium Supplements?

While there's not enough high-quality research to firmly recommend daily magnesium supplementation for all pregnant people, magnesium needs do increase during pregnancy. The recommended daily allowance (RDA) goes up by around 10%, from about 300–310 mg in non-pregnant individuals to 350–400 mg for those who are pregnant.

Since many people don’t meet these levels through diet alone, supplements can be helpful in addressing deficiencies.

Signs of Magnesium Deficiency

Low magnesium levels during pregnancy can result in:

  • Muscle cramps

  • Fatigue or weakness

  • Mood swings or anxiety

Some studies estimate that up to 80% of pregnant people consume less than 300 mg of magnesium daily, making supplementation a potentially useful option, especially in those with poor appetite or nausea.

Magnesium supplements are considered safe during pregnancy when taken within the recommended range. However, you should always speak with a healthcare provider before starting any supplement.

Benefits of Magnesium During Pregnancy

Some of the potential benefits of maintaining adequate magnesium levels while pregnant include:

  • Lower blood pressure: Magnesium may help reduce the risk of developing preeclampsia—a condition marked by high blood pressure during pregnancy.

  • Relief from muscle cramps: Research suggests that 200 mg of magnesium per day can help reduce leg cramps commonly experienced in later trimesters.

  • Protection against cerebral palsy: Magnesium sulfate is sometimes used in hospital settings to help reduce the risk of cerebral palsy in premature infants.

  • Better sleep: Magnesium may support more restful sleep and reduce fatigue during the day.

  • Improved mood: Some researchers believe a deficiency in magnesium could play a role in postpartum depression. Supplementing during pregnancy might reduce that risk.

  • Healthier outcomes for the baby: Getting enough magnesium may help lower the risk of low Apgar scores and reduce the need for NICU admission.

Which Magnesium Types Are Commonly Used in Pregnancy?

There are several forms of magnesium supplements available, and each serves a slightly different purpose:

Magnesium Sulfate

This type is often used intravenously in hospitals to manage or prevent severe preeclampsia and eclampsia. It’s also found in Epsom salt, which can be used in warm baths to relieve sore muscles and cramps.

Magnesium Citrate

This is a popular oral form used for leg cramps and mild constipation. In one study, 360 mg of magnesium citrate daily reduced the likelihood of early labor in at-risk individuals.

Magnesium Oxide

Commonly used for migraine relief during pregnancy. Doses up to 400 mg are generally well-tolerated, though it might delay milk production after birth in some cases.

Magnesium Bisglycinate

Known for its gentle impact on the stomach, this type can help reduce muscle cramping. A 300 mg dose may be effective for this purpose during pregnancy.

Are There Any Risks or Side Effects?

Though magnesium is generally safe, it can cause some side effects, especially when taken in high doses. These may include:

  • Diarrhea

  • Flushing or sweating

  • Nausea and vomiting

  • Headaches

  • Blurred vision

  • Muscle weakness

Magnesium can also interfere with the absorption of iron and zinc, which are also critical during pregnancy. Always consult your healthcare provider if you're taking multiple supplements.

If you experience side effects, your provider may advise switching to a different form of magnesium or reducing the dosage.

Quick Recap

Magnesium plays a vital role during pregnancy, from reducing the risk of high blood pressure and leg cramps to supporting the baby's overall health. While the evidence isn’t strong enough to recommend routine supplementation for everyone, it can be beneficial—especially for those with a known deficiency.

Most importantly, magnesium should be taken under the guidance of a healthcare professional to ensure it complements your nutritional needs without interfering with other supplements or medications.