Supplementing with magnesium may help to decrease the occurrence of pregnancy complications such as hypertension, preeclampsia, placental dysfunction, premature labor, growth restriction, and gestational diabetes especially in pregnant people from disadvantaged backgrounds. As with most vitamins and minerals, there are various forms of magnesium in supplements. Some forms of magnesium can be easier to absorb, and other forms may have a side effect of diarrhea. It’s important to consult a healthcare provider before starting any magnesium supplement and for individual guidance what form of magnesium best suits your needs. Our prenatal dietitian has combed through evidence-based research, spoken with other experts in the prenatal field, and has years of personal experience to break down exactly what to look for in a magnesium supplement for pregnancy.
Is a Magnesium Supplement Beneficial for Pregnancy?
Tracy Lockwood Beckerman, MS, RD, CDN, author of “The Better Period Food Solution ‘’, suggests it may not be necessary to take additional magnesium in pregnancy if you have a varied diet. Beckerman says, “Because the body demands more magnesium during pregnancy, it’s wise to read the label on your prenatal vitamin to ensure you are getting the daily recommended amount.” If your prenatal vitamin is lacking, you may need an add-on supplement.
Here are some conditions for which magnesium may be beneficial during pregnancy: Gastrointestinal (GI) issues: Many pregnant people deal with heartburn or gastroesophageal reflux disease (GERD) in pregnancy due to the increased abdominal pressure from the growing baby. Schlichter suggests magnesium can be helpful for GI spasms and nausea associated with pregnancy. In fact, magnesium carbonate is a common ingredient alongside calcium in antacid supplements to help calm stomach acid and alleviate heart burn sensation many pregnancy people are familiar with. Beckerman says, “For those with Crohn’s disease, celiac disease, ulcerative colitis, or have experienced excessive loss of fluids from either sweat or diarrhea, additional magnesium may help to ensure adequate levels in the body.” Leg cramps: One of the more pesky pregnancy discomforts can be restless legs or having leg cramps. This discomfort can get in the way of having a restful night of sleep throughout pregnancy. Some research has shown a 300 mg supplement of magnesium bisglycinate helps reduce the frequency and intensity of leg cramps during pregnancy. Insomnia: Pregnant people are often told to sleep as much as you can before the baby arrives. However, this can be challenging for those suffering from insomnia and poor sleep during pregnancy. Luckily, magnesium may help improve sleep. Research has shown that magnesium may modestly help to improve sleep quality and duration for some pregnant people. Gestational Diabetes: Gestational diabetes impacts between 1-14% of pregnancies and is characterized by impaired glucose tolerance and increasing insulin resistance. “Magnesium is involved in many steps of the insulin signaling pathway”, says Ryann Kipping MPH, RDN, CLEC, founder of The Prenatal Nutritionist. Supplementation has been shown to improve insulin sensitivity in women with normal or deficient levels of magnesium. Preeclampsia: Preeclampsia is high blood pressure and protein in the urine during pregnancy. Oral magnesium supplementation has been shown in some studies to decrease preeclampsia by reducing blood pressure in the last weeks of pregnancy. This is especially true for those who are deficient in magnesium.
Who May Not Benefit From Magnesium Supplements in Pregnancy
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 magnesium/day) could lead to toxicity. It is recommended to stay under 350 mg of magnesium from supplements (not including food) during pregnancy. If you eat a variety of magnesium-rich foods throughout your pregnancy and you don’t have any health conditions listed above, then you will likely not benefit from an extra magnesium supplement during pregnancy. We like that the form of magnesium in this supplement is the highly absorbable form magnesium bisglycinate. This means two glycine molecules are essentially giving a protective “hug” around the magnesium which can decrease the laxative effect magnesium might have. Glycine can also help promote good sleep and relaxation which could make it ideal to take this supplement before going to bed. This powder can simply be mixed into water or your desired beverage. It contains only magnesium, citric acid, and a little bit of monk fruit for sweetness which may not suit everyone’s taste. There are no other flavorings or colors added, 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. And pregnancy, let’s face it, can sometimes feel like an athletic event! Note it is a more expensive option compared to other magnesium supplements. Price at time of publication: $44.00 ($0.73 per serving) This prenatal contains 300 mg—75% Daily Value—of magnesium glycinate. If you’re not eating a lot of magnesium-rich foods or you’re magnesium deficient during pregnancy, this prenatal would greatly help to meet your daily magnesium needs. The glycinate form of magnesium is highly absorbable without causing an upset stomach. Besides being a good source of magnesium, this prenatal provides many other important nutrients needed during pregnancy such as folate, vitamin B12, choline, zinc, selenium, iodine, and vitamins A, C, and D. We also like that FullWell does third-party testing for contaminants like heavy metals, BPA, and pesticide residues in this supplement. One consideration for this prenatal vitamin is that the serving size is eight pills per day. Magnesium is a “bulky” mineral, which is one of the reasons why the pill count for this product is higher than other prenatals. 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 putting it into smoothies, yogurt, etc. A healthcare professional can give further guidance for what prenatal vitamin is best for your needs. 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. Price at time of publication: $50.00 ($1.67/serving) as a one time purchase This small, easy to take pill provides 250 mg—60% Daily Value—of magnesium oxide which can complement a well balanced diet or a prenatal vitamin that is low in magnesium. The oxide form helps make this supplement budget-friendly, but note it may not be so kind to your digestive system. Magnesium oxide could increase the risk for diarrhea for some people. However, if you’re dealing with pregnancy constipation this could be helpful, but it otherwise might cause some unwanted stomach discomfort. Price at time of publication: $6.00 ($0.05 per serving) CALM powder can be found unflavored, but we also appreciate it comes in flavors like raspberry lemon, orange, cherry, watermelon, or sweet lemon. The flavor is from natural organic flavorings and stevia for sweetness which some may or may not like. It’s third-party tested, vegan, gluten-free, and mixes great into a glass of water or smoothie. Price at time of publication: $25.00 ($0.45 per serving) Each scoop serving provides 300 mg—71% Daily Value—of magnesium gluconate. This form is well absorbed and has a lower risk of causing digestive problems. Each serving also provides 15% Daily Value of calcium and 125% Daily Value of vitamin D. Natalist created this evidence-based product with the guidance of an Obstetrics and Gynecology doctor (OBGYN) and dietitian. Their products are all geared for women and pregnancy, and this supplement was created specifically to help with bone development, strength, and to promote rest and relaxation during pregnancy. It’s recommended to mix this raspberry flavored powder—which is sweetened with stevia—into 8-10 ounces of warm or cold water, depending on your preference. Although this product is not third-party tested, they do test for contaminants and heavy metals in house. It is also vegetarian and gluten-free. Price at time of publication: $35.00 ($2.33 per serving) This third-party tested gummy is vegan, non-GMO, gluten-free, and doesn’t contain any gelatin. It’s available in sweet watermelon and tangy tangerine flavors. The citrus flavor can be especially pleasing to nauseous moms. Each gummy contains 84 mg—20% Daily Value—of magnesium citrate, which is a well absorbed form and not likely to cause any stomach discomfort. Adults are recommended to take up to four gummies daily, but based on your needs you may need less than this especially if other supplements you take have magnesium. Note it’s not recommended to take all four gummies at once—they should be spread out over the day which may be hard to remember during pregnancy. Each gummy provides 1.5 grams of sugar, so if you take more than one per day this may be important to 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. Price at time of publication: $20.00 ($0.17 per gummy) Many risk factors that contribute to GDM are not modifiable (age, ethnicity, family history, etc.), but getting adequate nutrition—including magnesium—can also impact 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. Inositol, a form of a B vitamin, is an insulin sensitizer and used for blood sugar management. Utzy Magnositol PM has combined these two blood sugar supporting nutrients into one convenient supplement. This powder supplement provides 200 mg—48% Daily Value—of the highly absorbable magnesium bisglycinate along with one gram of myo-inositol. Inositol improves insulin sensitivity, so having this in a magnesium supplement may be beneficial for someone at risk for gestational diabetes. Before taking this supplement, check with a healthcare provider to make sure the inositol and magnesium is the best choice for your needs. Also note this supplement is not clearly third-party tested. Price at time of publication: $33 ($1.10 per serving) We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are third-party tested and certified by one of three independent, third party certifiers: USP, NSF, or ConsumerLab.com. It’s important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.
What to Look For in Magnesium Supplements for Pregnancy
Third-Party Testing
Supplements that are third-party tested are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. However, it’s important to note:
Third party testing does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.Not all third-party testing is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing. The third party certifications we can trust are: ConsumerLab.com, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations. Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.Just because a supplement is not tested by one of these three companies, it does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer, and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.
Form
Magnesium can be found in a variety of forms. It comes as pills, a powder, liquid, or gummies so you can choose the type that you tolerate best. Furthermore, different types of magnesium may be better tolerated than others, so it’s important to read labels and consult with a healthcare provider before choosing a magnesium supplement. Here are some of the most common types of magnesium that one could supplement with in pregnancy.
Magnesium oxide- this form is often inexpensive but most likely to cause diarrhea. This form is common in milk of magnesia and produces a fast acting laxative effect. Magnesium citrate, chloride, and bisglycinate- these forms are water soluble, which means they are better absorbed in the gut and less likely to cause diarrhea unless taken at very high doses. Magnesium chloride- if you need to take large doses of magnesium, (due to excessive losses or severe deficiency) this form is considered the most effective while not causing as much diarrhea. It is best as a liquid or tablet supplement. Magnesium carbonate- antacids commonly use this form, although it is not absorbed very well. It may have a laxative effect for some people.
Ingredients & Potential Interactions
It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included, relative to the recommended daily value of that ingredient. Please bring 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. 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, vitamin K, and/or boron so it’s important to consider overall supplementation if you also take a multivitamin or prenatal vitamin containing these nutrients as well. 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.
Magnesium Dosage
The Recommended Dietary Allowance (RDA) for magnesium for pregnancy is:
Women 19-30 years old- 350 mgWomen 31-50 years old- 360 mg
How Much is Too Much?
Our kidneys will dispose 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.
Why Trust Verywell Family
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. Schlichter suggests a supplement may be helpful for those with a history of deficiencies, disordered eating, or eating disorders. However, a healthcare professional can give individual recommendations for your needs. Schlichter says, “These foods provide other essential nutrients for a well-balanced diet for pregnancy.” She 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.
