The 8 Best Magnesium Supplements for Pregnancy of 2024, According to Dietitians

Magnesium needs increase during pregnancy, and many women may not get enough magnesium from diet alone. While magnesium is found in a variety of foods, including nuts, seeds, green leafy vegetables, legumes, and whole grains, it is estimated that nearly half of Americans consume below the Estimated Average Requirement (EAR). Magnesium is an essential mineral needed for protein production, muscle and nerve function, stress regulation, bone health, blood pressure, and blood sugar control.

Getting enough magnesium during pregnancy is important because it may help decrease the risk of some pregnancy complications, including hypertension, preeclampsia, preterm labor, growth restriction, and gestational diabetes. In addition, some research shows that certain forms of magnesium can also help promote relaxation, improve sleep, reduce muscle cramping and restless leg syndrome.

Our prenatal dietitian combed through evidence-based research and spoke with other experts in the prenatal field to break down exactly what to look for in a magnesium supplement for pregnancy. When selecting our top picks, we analyzed the quality of ingredients, form, dosage, and safety, prioritizing third-party tested products. Our Review Board reviewed this article for medical accuracy and integrity surrounding magnesium supplements for pregnancy. 

Should I Take a Magnesium Supplement During Pregnancy?

Here are some conditions for which magnesium may be particularly beneficial during pregnancy:

• Gastrointestinal (GI) issues: Heartburn or gastroesophageal reflux disease (GERD) in pregnancy can be common. Sarah Schlichter, MPH, RDN, suggests magnesium can be helpful for pregnancy heartburn and nausea. Magnesium carbonate is a common ingredient alongside calcium in antacid supplements to help calm stomach acid and alleviate heartburn. If you are already taking antacid supplements, consult a healthcare professional before taking an additional magnesium supplement to make sure you are not getting too much magnesium.

Certain forms of magnesium, including magnesium citrate and magnesium oxide, may help to alleviate occasional constipation during pregnancy. 

• Leg cramps and restless leg syndrome: Some research has shown a 300 mg supplement of magnesium bisglycinate helps reduce the frequency and intensity of leg cramps during pregnancy.
• Insomnia can be a challenge throughout pregnancy, especially in the third trimester. Luckily, magnesium may help improve sleep. Research has shown that magnesium may modestly help to improve sleep quality and duration.
• Gestational Diabetes impacts between 1–14% of pregnancies and is characterized by impaired glucose tolerance and increasing insulin resistance. Magnesium supplementation could help improve insulin sensitivity in women with normal or deficient levels of magnesium.
• Preeclampsia is high blood pressure and protein in the urine during pregnancy. Oral magnesium supplementation may help decrease preeclampsia by reducing blood pressure in the last weeks of pregnancy. This is especially true for those who are deficient in magnesium.

If you eat a variety of magnesium-rich foods throughout your pregnancy (or if you are getting enough magnesium from your prenatal vitamin and diet combined) and you don’t have any health conditions listed above, then you may not benefit from adding a magnesium supplement during pregnancy. A healthcare professional can give further individual guidance.

To get more magnesium-rich foods, Schlichter suggests adding nuts and seeds to a salad or oatmeal, snacking on some dark chocolate or low-fat dairy, or aiming to have a few bean or legume-based meals each week, such as black bean tacos or adding lentils to pasta.

Our Favorites

• Best For Sleep: Thorne Magnesium Bisglycinate
• Best For Headaches: Nature Made Magnesium Oxide
• Best Budget-Friendly: NOW Magnesium Glycinate
• Best Prenatal Vitamin with Magnesium: FullWell Women’s Prenatal Multivitamin
• Best For Constipation Relief: Pure Encapsulations Magnesium Citrate
• Best Gummy: Trace Magnesium Stress Relief Gummies 
• Best For Bone Health: Natalist Magnesium Plus 
• Best for Gestational Diabetes: Utzy Naturals Magnositol PM Magnesium & Inositol

Best For Sleep

Thorne Research Magnesium Bisglycinate Powder

$48 at Amazon $48 at Target $48 at Walmart

Why We Recommend It

With high-quality ingredients and strong third-party testing, Thorne Magnesium Bisglycinate is our top choice for a magnesium supplement for pregnancy, especially if you're looking for better rest (and who isn't?). Each serving provides 200 milligrams of magnesium, more than half the daily value recommended during pregnancy. 

We like that this supplement contains the highly absorbable form called magnesium bisglycinate. This means two glycine molecules are essentially giving a protective barrier around the magnesium, which improves its absorbability and decreases the potential laxative effects of magnesium supplements. Both magnesium and glycinate may help promote relaxation and improve sleep quality. This may be an especially important consideration if you are struggling with pregnancy insomnia.

This powder can simply be mixed into water or any other beverage. It contains just three ingredients (magnesium, citric acid, and monk fruit concentrate), with no artificial flavorings or colors. It is also free of gluten, dairy, and soy. We like that this product is NSF Certified for Sport, meaning it is third-party tested for ingredients, contaminants, and prohibited substances for athletics.

But Take Note

It contains the non-nutritive sweetener monk fruit, which may not suit everyone’s taste. It is also more expensive compared to other magnesium supplements on the market. 

Product Details:

• Supplement Type: Powder
• Form: Magnesium bisglycinate
• Dose: 200 mg
• Recommended Use: Mix 1 scoop with at least 8 ounces of water daily.
  

Best For Headaches

Nature Made Magnesium Oxide 250 mg

$7 $5 at Amazon $7 at Target $11 at Walmart

Why We Recommend It

Nature Made Magnesium Oxide 250 mg is third-party tested for ingredient amounts and potential contaminants. This small, easy-to-take pill provides 250 milligrams of magnesium, around 70% of the recommended intake during pregnancy.

Magnesium oxide is one of the least expensive forms of magnesium supplements, but it is less bioavailable compared to other forms on our list. This means less magnesium is absorbed and used by the body. However, it is still effective in boosting your magnesium levels. Additionally, this form of magnesium can be helpful in alleviating occasional constipation, and it’s the preferred form to help treat and prevent migraines during pregnancy.

This supplement is gluten-free and contains no synthetic dyes or artificial flavors. 

But Take Note

The oxide form helps make this supplement budget-friendly, but note that this form can cause gastrointestinal side effects like diarrhea in some people. It also contains emulsifiers and other additives, including polysorbate 80. While this is considered safe to consume, some may choose to avoid these ingredients. 

Product Details:

• Supplement Type: Tablet
• Form: Magnesium oxide
• Dose: 250 mg
• Recommended Use: Take one tablet daily with water and a meal. 

Best Budget-Friendly

Now Magnesium Glycinate

$32 $20 at Amazon $21 at Walmart View on Vitacost

Why We Recommend It

While magnesium oxide is typically the least expensive, it is less bioavailable and may not be tolerated well by everyone. NOW Magnesium Glycinate is a budget-friendly alternative, but still contains the highly absorbable and well-tolerated form of magnesium. It is also the form that may be helpful to promote sleep.

This supplement is third-party tested for purity and potency, including heavy metal testing, and comes from a reputable, quality brand that also does its own in-house quality testing. Each two-tablet serving contains 200 milligrams of magnesium bisglycinate, a little more than half of the RDA for pregnant people. 

It contains no artificial colors or flavors and is free of common allergens, but it is produced in a facility that processes gluten, dairy, soy, and other potential allergens, so it may not be suitable for those with severe food allergies.

But Take Note

This is a lower dose magnesium supplement with 100 milligrams per capsule, making it a good option if you are looking for a magnesium boost. But may not be enough if your diet and prenatal are low in magnesium. 

Product Details:

• Type: Powder
• Form: Magnesium bisglycinate
• Dose: 200 mg
• Recommended Use: Mix 1 scoop with at least 8 ounces of water daily. 

Best Prenatal Vitamin with Magnesium

Fullwell Women's Prenatal Multivitamin

$50 at Amazon View on Fullwellfertility.com

Why We Recommend It

Prenatal multivitamins vary in their amounts of vitamins and minerals. FullWell Prenatal contains more magnesium than you’ll typically find in a prenatal multivitamin with 300 mg of magnesium—85 percent daily value during pregnancy. This amount and form may also help with reducing leg cramps during pregnancy. It contains magnesium glycinate, the highly absorbable, well-tolerated form found in our top pick. We also like that FullWell does third-party testing for contaminants like heavy metals, BPA, and pesticide residues.

In addition to being a good source of magnesium, this prenatal provides many other important nutrients needed during pregnancy, such as folate, vitamin B12, calcium, choline, zinc, selenium, iodine, and vitamins A, C, and D. Note that this prenatal does not contain iron, an important mineral during pregnancy. However, iron can compete for absorption with certain nutrients (like calcium), so it may be beneficial to take iron separately if needed.

But Take Note

One consideration for this prenatal vitamin is that the serving size is eight pills per day to be able to pack in all of the nutrients it provides. Ultimately, determining the number of pills you feel comfortable taking in a day needs to be considered. Another option is breaking open the pills and mixing them into foods or beverages like smoothies or yogurt.

Also, note this prenatal is more expensive compared to some other prenatal supplements. FullWell prenatal can be a one-time purchase, or it can be purchased as a subscription for a slightly lower price point. 

Product Details:

• Supplement Type: Capsule
• Form: Multivitamin vitamin with Magnesium Glycinate 
• Dose: 300 mg of magnesium
• Recommended Use: 8 capsules daily

Best For Constipation Relief

Pure Encapsulations Magnesium (Citrate)

$20 at Amazon $20 at Walmart View on Pureformulas.com

Why We Recommend It

Magnesium citrate is another popular and widely available form of magnesium supplement with high bioavailability. While it’s best to prevent or treat constipation by increasing your fiber and water intake, a magnesium citrate supplement is a safe way to help encourage bowel movements. Magnesium citrate pulls water from the body into the gastrointestinal tract, which can create a laxative effect that may help relieve occasional constipation during pregnancy. 

Pure Encapsulations tests all raw materials for identity, potency, contaminants, and heavy metals in addition to being an NSF-registered facility. It contains 150 milligrams of magnesium per serving, a little less than half the RDA for women during pregnancy. 

This magnesium citrate is certified gluten-free, non-GMO, and vegan. 

But Take Note

Potential side effects of magnesium citrate include cramping, gas, and diarrhea, but these are typically seen at higher dosages. Be sure to contact a healthcare professional if your constipation persists or if you experience excessive diarrhea after supplementing, which can lead to dehydration and electrolyte loss. Note that this is a lower-dose supplement, so these side effects would be unlikely. It provides less than half the RDA, so if you are using it to boost your magnesium status, it may not be enough to meet your needs if your diet and prenatal are low in magnesium. 

Product Details:

• Supplement Type: Capsule
• Form: Magnesium citrate
• Dose: 150 mg
• Recommended Use: Take one tablet daily with water and a meal. 

Best Gummy

Trace Minerals Magnesium Gummies Watermelon Flavor

$28 $23 at Amazon View on Traceminerals.com

Why We Recommend It

Trace Minerals Magnesium Gummies could be your best choice if you’re feeling nauseous and don't want to take pills. It’s third-party tested for purity and potency and contains 84 milligrams of magnesium citrate per gummy, with a recommended serving size of up to four gummies per day. This four-gummy dose provides 336 milligrams, which is 80% Daily Value.

We like that you can control the dose easily to meet your individual needs. For example, if your prenatal includes some magnesium and you are getting some from your diet, you may only need one or two gummies. Magnesium citrate is highly bioavailable, but it can have a laxative effect, so if you are taking the full four-gummy dosage, it is recommended to spread them throughout the day instead of all at once.

This supplement is non-GMO, gluten-free, and free of artificial flavorings and colorings. It also doesn’t contain any gelatin, making it a vegan-friendly gummy option. It’s available in sweet watermelon and tangy tangerine flavors.

But Take Note

The magnesium amount in each gummy is less than other magnesium supplements, but this can also help tailor the dose to your individual needs. Magnesium citrate can cause GI side effects like diarrhea in some due to its potential laxative effects, but the low dose per gummy allows you to adjust as needed.

Product Details:

• Supplement Type: Gummy
• Form: Magnesium Citrate
• Dose: 84 mg
• Recommended Use: Take 1–4 gummies daily, depending on your needs. 

Best For Bone Health

NATALIST Magnesium Plus 300 mg

$34 at Amazon View on Natalist.com

Why We Recommend It

If you’re looking for a magnesium powder with added nutrients to support bone health, we recommend Natalist Magnesium Plus. We like Natalist Magnesium Plus because it's a researched-backed formulation containing magnesium, vitamin D3, and calcium. These nutrients all work together to play an important role in bone health. 

Natalist is a company focused on supplements for the needs of women’s stages of fertility, pregnancy, and postpartum, with science-backed formulations developed by OBGYNs and Registered Dietitians. While not third-party tested, they have strong in-house testing for purity and potency, including heavy metal testing. 

Each scoop serving provides 300 milligrams of magnesium gluconate, more than 80% Daily Value. Each serving also provides 15% Daily Value of calcium and 125% Daily Value of vitamin D. It’s recommended to mix this raspberry-flavored powder into 8–10 ounces of warm or cold water, depending on your preference. It is lightly sweetened with stevia, with no artificial flavors or colorings. When we tried this, we loved its subtle, sweet flavor and the fact that it helped keep us hydrated.

But Take Note

Because this supplement contains additional vitamins and minerals, be sure to check your prenatal vitamin or any other supplements you are taking to ensure you are not exceeding the Tolerable Upper Intake Level (UL) for any nutrient. These can be found here on the NIH website. 

Note that magnesium gluconate is well absorbed but can cause GI side effects at high dosages.

Product Details:

• Supplement Type: Powder
• Form: Magnesium gluconate
• Dose: 300 mg
• Recommended Use: Stir one scoop into 8–10 ounces of warm water until fully dissolved (daily). 

Best for Gestational Diabetes

Utzy Naturals Magnositol PM Magnesium & Inositol

$36 at Amazon $34 at Utzy.com

Why We Recommend It

Gestational diabetes mellitus (GDM) is a type of diabetes that can happen during pregnancy and usually goes away after the birth of the baby. Many risk factors that contribute to GDM are not modifiable (age, ethnicity, family history, etc.), but getting adequate nutrition—including magnesium—can also impact the risk for GDM. Magnesium is involved in the insulin signaling pathways and has been shown to improve insulin sensitivity in people who have normal or low levels of magnesium.

We like that this supplement also has inositol. Along with diabetes medication, inositol has been shown to improve blood sugar management.

Utzy Magnositol PM has combined these two blood sugar-control supporting nutrients into one convenient supplement. This powder supplement provides 200 mg—about 50 percent Daily Value—of the highly absorbable magnesium bisglycinate along with one gram of myo-inositol. It is gluten-free and does not contain artificial colors, flavors, or any sweeteners.

But Take Note

Before taking this supplement, check with a healthcare provider to make sure the inositol and magnesium are the best choices for your needs. This supplement is internally tested for purity and potency but does not clearly state any third-party testing. 

Product Details:

• Supplement Type: Powder
• Form: Magnesium bisglycinate
• Dose: 200 mg 
• Recommended Use: Place one heaping teaspoon of powder in an 8-ounce glass; add approximately two to three ounces of water. Let it fizz, then stir until dissolved. Fill the rest of the glass with water.

Forms of Magnesium We Recommend

Some forms of magnesium supplements are more easily tolerated and absorbed, while others can have gastrointestinal (GI) side effects and should mostly be used for occasional constipation relief. We recommend consulting a healthcare provider before starting any magnesium supplement to get individual guidance on what form and dose of magnesium best suits your needs. 

The four most commonly used forms in oral magnesium supplements include glycinate, citrate, gluconate, and oxide. All of these forms will increase your magnesium levels, but they have different absorption rates and vary in their potential side effects and uses.

• Magnesium glycincate (or bisglycinate) is magnesium bound to the amino acid glycine. It is considered the easiest to absorb, most bioavailable, typically well-tolerated (easy on the stomach), and maybe the best form to promote relaxation and improved sleep. 
• Magnesium citrate is also well absorbed, but it can have a laxative effect and, therefore, may be used for occasional constipation relief. Some studies show magnesium citrate may also help to improve blood sugar control and blood pressure. 
• Magnesium gluconate is another well-absorbed form, but it can cause GI side effects (like diarrhea) in some, but it is typically better tolerated than magnesium oxide. 
• Magnesium oxide is the most inexpensive form of the three, but it is less bioavailable than the other forms and can also have a laxative effect, often used for occasional constipation relief. Magnesium oxide is also sometimes used for the prevention and relief of migraines during pregnancy.

Our Supplement Review Process

In reviewing and researching prenatal vitamins, we consult with experts and our own in-house Registered Dietitians. We support supplements that are evidence-based and rooted in science, and we value certain product attributes that we find to be associated with the highest-quality products. In order to find the best magnesium supplements for pregnancy, we closely consider several factors, including quality of ingredients, third-party testing certifications, and comparing different forms and dosages. For prenatal supplements especially, we prioritize products that are third-party tested for purity and potency, as the FDA does not review dietary supplements for safety and effectiveness before they go to market.

Additionally, magnesium supplements can vary widely in price, so we also consider a range to meet all budgets because a higher price does not necessarily equal higher quality. 

While we hope this serves as a guide, we recommend consulting with your healthcare provider before taking any supplements. 

Our Experts

• Sarah Schlichter MPH, RDN is a Registered Dietitian and founder of Bucket List Tummy, a practice that specializes in family nutrition.
• Tracy Lockwood Beckerman, MS, RD, CDN, is a Registered Dietitian specializing in women’s health and author of "The Better Period Food Solution".
• Ryann Kipping, MPH, RDN, CLEC, is a Registered Dietitian and founder of The Prenatal Nutritionist.
• Anne Cook Carroll, MS, RD, CDN, is a Registered Dietitian who works with patients, including pre and post-natal women, to meet their health goals.

Magnesium Supplement Dosage & Safety

Dosage

The Recommended Dietary Allowance (RDA) for magnesium for pregnancy is:

• Pregnant women 19–30 years old: 350 mg
• Pregnant women 31–50 years old: 360 mg

Our kidneys will get rid of excessive magnesium, so toxicity is rare. However, “side effects of supplementing with too much magnesium may include diarrhea, nausea, and abdominal cramping.” says Kipping.

She also notes that too much magnesium from food does not pose risks for mom or baby, but it is possible to supplement with too much. The established Tolerable Upper Intake level (UL) for supplemental magnesium during pregnancy is 350 mg. A healthcare professional can give further guidance for what is the best amount of magnesium for your needs during pregnancy. Getting too much magnesium, especially in the third trimester, could cause high level of magnesium in the blood which can increase risk for floppy infant syndrome (hypotonia).

Ingredients and Potential Interactions 

It is essential to read the ingredient list and nutrition facts panel of a supplement carefully to know which ingredients are included (and how much of each), relative to the recommended daily value of that ingredient. Please take the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

It’s important to consider all forms of supplemental magnesium during pregnancy. Beckerman cautions, “Those that regularly take antacids during pregnancy (which is quite common to help relieve pregnancy-related heartburn or other common GI discomfort) may not benefit from taking a magnesium supplement.” 

Magnesium is one of the top ingredients in antacids, so it may not be wise to overload the system with too much magnesium, which can lead to diarrhea and abdominal cramps. Research has shown that supplemental intake from antacids (providing more than 5,000 mg of magnesium/day) could lead to toxicity. It is recommended to stay under 350 mg of magnesium from supplements (not including food) during pregnancy.

Magnesium may interact with certain medications or other supplements you may be taking. If you are also using bisphosphonates, antibiotics, diuretics, or proton pump inhibitors (PPIs), then consult with a healthcare provider before adding any magnesium supplement. 

Some supplements may combine magnesium with calcium, vitamin D, and vitamin K (since these nutrients work together), so it’s important to consider overall supplementation if you also take a multivitamin or prenatal vitamin containing these nutrients.

Lastly, take caution if you are supplementing with high doses of zinc (>142 mg/day), as this can interfere with magnesium absorption and disrupt the magnesium balance in the body.

Who We Are

Casey Seiden is a registered dietitian nutritionist and certified diabetes care and education specialist based in New York City. Casey works at Maternal Fetal Medicine Associates, the premier maternal-fetal medicine practice in Manhattan, where she provides nutrition therapy and counseling to women with high-risk pregnancies. She is also the founder of Casey Seiden Nutrition, a virtual private practice specializing in a non-diet approach to diabetes care and women’s health.