Prenatal Vitamins by Dr. Stacey Pereira

The truth about prenatal vitamins, ladies! What is a prenatal vitamin? What isn’t it? Why does it matter?! Why does my OB keep telling me to take my prenatal vitamin if I eat lots of veggies, or I’m vegetarian or vegan? What about prenatal gummies? My gummies make me nauseous, now what?!

The answer to these questions is fairly simple and straightforward. Learn about what matters in pregnancy, doctors’ recommendations, and how to choose a prenatal vitamin.

The truth about prenatal vitamins is that most of the world does not take a “prenatal vitamin.” Hard stop. Only folic acid!

Research behind appropriate vitamin supplementation in pregnancy is centered around folic acid and now DHA (docosahexaenoic acid), an omega-3 fatty acid. The rest of the American “prenatal vitamin” ingredients is standard vitamin supplements–not centered around pregnancy. These “prenatal vitamins” do not follow any specific guidelines. Vitamin supplementation is based on trying to increase what may be lacking from a non-balanced or diverse diet. The diet may lack the appropriate vegetable diversity and some essential fatty acids–the fat-soluble vitamins A, D, and K “ADEK”, B vitamin series, rare minerals, iron, and calcium. However, the women’s multivitamin discussion outside of pregnancy is for another day (and we’ll have a post!).

In the last century it became a well-known fact that folic acid deficiency led to increased rates of spina bifida ( and some rare congenital heart defects. In a pregnant woman’s diet, 400 mcg of folate or folic acid (which are metabolites of each other) are necessary in order to support appropriate fetal development– especially in the first 4-12 weeks of pregnancy. In essence, your folate levels should be high, if possible, one month PRIOR to pregnancy. Meaning, if you are able to plan for your pregnancy, you should be taking supplementation 1-2 months prior to conceiving in order to have an optimal level of folate. Great diet sources for foods high in folate are primarily dark leafy greens, beans, whole grains and others. Here is a list of diet-based folate sources: Folate (Folic Acid) – Vitamin B9 | The Nutrition Source.

Due to this known folic acid deficiency, however, it became common practice to supplement the general population diet with folate–especially in wheat-based products such as cereals and bread. In the US and Canada, a widespread folate supplementation mandate was instituted in 1998 and exists until this day.  According to a Harvard University study, there is thought to be a 50% decrease in rates of spina bifida in infants due to the increase of folates in the foods. Nowadays, diet-based folic acid deficiency is thought to be extremely rare in the US; however, the folate supplementation advisory still stands worldwide. See the Harvard Health article for more details: The ups and downs of folic acid fortification – Harvard Health.

The vast majority of “prenatal vitamins” contain well over the standard 400 mcg dosing of folate or folic acid recommendation–mostly due to concerns regarding genetic variance of potential absorption. There really is no such thing as “overdosing” on folic acid, as your body will eliminate anything it doesn’t need. There are specific cases where your obstetrician will recommend much higher-than-standard dosing of folic acid, for example, if you have a personal or family history of spina bifida, are carrying a twin pregnancy,  or have a child that was born with spina bifida. There are also instances where, if you have a medical condition or medications that may decrease folic acid absorption, higher doses are recommended. In these cases, the general recommendation is 1000- 4000mcg daily–consult with your doctor.

DHA supplementation is a newer recommendation. It is an omega-3 fatty acid that is essential in brain development. Due to concerns regarding mercury exposure and the advisory to limit seafood consumption to 2 servings a week– overall dietary consumption of DHA, especially in western countries, is below what is thought to be optimal. No specific safe or essential levels have been established. Sources of this omega include vegetable oils, seafood (which must be consumed in moderation), and supplementation. Hence, why many “prenatal vitamins” either contain DHA or come with a separate DHA supplement. 

Other than folic acid and DHA there are no other specific recommendations for vitamin supplementation in pregnancy! There are instances regarding concerns for anemia or calcium deficiency that may result from milk production or breastfeeding; however, your doctor will be checking your blood counts for anemia throughout your pregnancy. If you consume dairy products, calcium deficiency is rare. If you do not consume dairy products, a calcium supplementation is also recommended.

From here spawns the American “prenatal vitamin.” The prenatal vitamin is a generic approach to potential dietary deficiencies of folic acid and DHA supplementation in women who are or may become pregnant. While folic acid is a requirement in the United States to be sold as a “prenatal vitamin”, DHA is not, hence, the marketing surrounding “prenatal plus” or “prenatal with DHA.” The large number of supplements in these one-stop-shop types of vitamins creates a rather large pill. A larger pill can be hard to swallow, so look for something coated to ease swallowing. For those ladies that have trouble swallowing a larger pill, there is a “mini-pill” on the market. It is more costly and does not contain the vast array that other vitamins do. My personal recommendation is that if you have trouble swallowing a larger pill, opt for separating your supplements. For example, you can take DHA and folic acid separately–these are the essentials. 

So, Doc, what about prenatal gummies?

Gummy prenatal vitamins are great! The vast majority of brands contain exactly the same as what the solid version does and in the same amounts. The caveat is that the gummy versions have difficulty binding large positive ions, meaning iron and calcium (Fe2+ and Ca2+). If you are prone to anemia or do not incorporate dairy products into your diet, you should consider an iron or calcium supplement in addition to your prenatal gummy.

Doc, I’m so nauseous! Or I feel nauseous after I take my vitamins.

Certain rare minerals can create nausea on an empty stomach–especially zinc. Make sure to take your prenatal vitamins with food. Also, some women have sensitivity to iron supplementation. If you are having nausea with your prenatal vitamins or are having difficulty taking it due to nausea of pregnancy, discuss with your doctor about taking gummies or folic acid and DHA separately. 

Doc, I follow a vegetarian or vegan diet. Are there any special considerations? 

Yes! Unfortunately, in western culture, vegetarian and vegan diets are prone to high carbohydrates and may lack essential nutrients. I highly recommend a well-rounded prenatal supplement as well as an additional iron supplement. For those of us who do not consume animal proteins, we are prone to weak connective and muscular tissue as well as anemia. If you are vegetarian or vegan and pregnant, it is especially important to concentrate on your protein intake as well as to take an iron supplement. This is why many doctors recommend a protein supplement, once daily, which usually comes in the form of a shake. However, you can get the supplements that you need dietarily; see a recommended list from Harvard University: Protein | The Nutrition Source.

Doc, why are some prenatal vitamins so much more expensive than others? 

To be honest, the inflated prices of some prenatal vitamins is mostly marketing bluff. If you are conscientious about sourcing (i.e. you have preferences about where it is made) or ascribe to guarantees regarding ‘organic’ or ‘vegetarian capsules’, this is where the disparity regarding pricing primarily comes from. Remember that none of these supplements are “grown” so there is no exposure to pesticides, hence, this invalidates any claims regarding ‘organic’ in the traditional sense. It is true that some coated capsules contain bovine (gelatin) based materials. If this is against your preferences, make sure to look for vegetarian capsules which are usually made from cellulose and are not necessarily more expensive than coating which is gelatin. 

In conclusion, the American “prenatal vitamin” is a one-stop-shop that is thought to supplement any type of diet or lifestyle in order to best support pregnant women throughout their pregnancy and breastfeeding. Yes! You should continue to take your prenatal vitamin until your child is weaning from breastfeeding. However, many of us have different challenges and preferences such as size of pill, issues with nausea, medical indications, and dietary requirements. Make sure to discuss with your obstetrician if you have questions regarding your prenatal vitamin and check the ingredient list for folic acid and DHA!

With much love and support,

Dr. Stacey Pereira

Meet Dr. Stacey Pereira

Dr. Pereira is a Brazilian-American who grew up in the Pacific Northwest and Northeastern Brazil (Fortaleza!). She is fluent in Portuguese and Spanish . Dr. Pereira is a passionate OB/GYN who loves caring for women during their pregnancy as well as the full scope of gynecology. Her expertise includes high risk pregnancies, preventative care as well as minimally invasive Gynecologic care.

Dr. Pereira considers herself an integrative medicine provider caring for the whole person taking into account mental,  physical, and psycho-social issues. Dr Pereira incorporates hormonal and non hormonal therapies and procedures into her treatments for cycle related issues, mood, perimenopause, and  postmenopause.

She also specializes in minimally invasive surgery with a unique emphasis in robotics, having received extensive experience in one of America’s top training hospitals in Chicago, IL. Dr. Pereira is passionate about advancing clinical and surgical women’s healthcare and has been published and presented research at multiple medical society national conferences.

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