Recommending a Prenatal Supplement

Recommending a Prenatal Supplement

"Nutrition during pregnancy cannot be boiled down to supplements alone. Instead, the majority of an individual’s nutrition needs should be met through diet while targeted supplements are used to fill nutrient gaps and ensure adequate amounts of key nutrients during pregnancy"

By Erika Weber MS, RD, CD & founder of Cultivated Nutrition

Nutrition during pregnancy plays a crucial role in the development of a baby as well as the health of the expecting mother. Maternal nutrition both before and during pregnancy has impacts on fertility, mental health, and risk of pregnancy complications. In regards to the fetus, maternal nutrition can impact the risk for premature delivery, fetal malformations, stillbirth, development of asthma and allergies, neurocognitive and behavioral development, and overall risk of disease later in life (1). 

Unfortunately, nutrition during this time is often glossed over with the common recommendation to simply, “take a prenatal”. However, not all prenatal supplements are created equally and this post will take you through some key considerations for selecting an appropriate supplement.

The Role of Diet

Before we dive in, it’s important to recognize that having a solid foundation of nourishing and nutrient-dense foods should not be discounted. Nutrition during pregnancy cannot be boiled down to supplements alone. Instead, the majority of an individual’s nutrition needs should be met through diet while targeted supplements are used to fill nutrient gaps and ensure adequate amounts of key nutrients during pregnancy.

Important Considerations

Third Party Testing

Supplements are not regulated by the FDA which means they are not routinely evaluated for safety or effectiveness (2). To ensure supplements are safe and appropriate to consume, look for indicators on the label or website that reports a supplement has been third-party tested. Companies such as Consumer Lab, NSF International, and U.S. Pharmacopeia (USP) test supplements for accuracy, potency, and the presence of contaminants such as heavy metals (3).

More is Not Always Better

Just because a specific vitamin or mineral provides a health benefit, does not mean that more of that nutrient is better. Approach single-nutrient supplements with caution and intention. Often, these supplements provide a much higher dose than is found in multivitamins and may put an individual at risk of excess intake or toxicity. 

When to Start Taking a Prenatal Multivitamin

Ideally, females should take a prenatal multivitamin prior to conception. There are many key nutrients, such as folate, iodine, and choline that have a significant impact in the first several weeks of pregnancy. A good recommendation is to start taking a prenatal multivitamin 3 months prior to conception. 

Key Nutrients to Include


Folate, also known as Vitamin B9, plays an essential role in the closure of the neural tube during the first trimester of pregnancy. This nutrient is especially important to include preconception as this process occurs before many women know they are pregnant (4,5). In addition to preventing neural tube defects (NTD), folate also plays a role in DNA synthesis and cell division.

During pregnancy, it’s recommended to include a supplement with at least 400 mcg/day folic acid. More may be necessary if individuals have a history of pregnancies with NTDs (4).

Of note, there has been a recent increase in the availability of methylated folate (5-MTHF) as an alternative to folic acid in prenatal supplements, especially targeted to those with specific MTHFR gene variants (6). While the emerging research warrants consideration, an in-depth review is outside the scope of this article. I encourage healthcare professionals to collaborate with a client’s care team to determine the most appropriate folate supplementation and dose for each individual.

Vitamin D

Vitamin D is a fat-soluble vitamin that aids in cell growth and differentiation, regulation of the immune system, and skeletal development (7,8). Low levels of Vitamin D are associated with small-for-gestational age (SGA) and low birth weight infants.

Research shows people may need much more than the RDA of 15 mcg/day to maintain adequate Vitamin D levels with many requiring 25-50 mcg/day or more (8,9). Vitamin D status should be assessed routinely by testing the level of 25-hydroxyvitamin D.


Choline during pregnancy plays a role in brain and nervous system development, placental function, and gene expression. Some research suggests that choline may also play an important role in preventing neural tube defects (10,11).

The AI (Adequate Intake) for choline during pregnancy is 450 mg/day, however it’s estimated that 90% of females don’t consume enough choline to meet the AI (12). In addition, many prenatal multivitamins don’t include choline. Look for a multivitamin that includes 150 mg or more of choline or include a separate choline supplement for at-risk folks.


This mineral is a key component of thyroid hormones and essential for thyroid health. During pregnancy, iodine plays a role in the development of the central nervous system and inadequate maternal iodine intake is associated with poor intellectual development and congenital hypothyroidism. In more severe cases, iodine deficiency has been associated with miscarriage, stillbirth, and birth defects.

The RDA for iodine increases during pregnancy to 220 mcg/day. Per the American Thyroid Association recommendations for pregnancy, look for a prenatal multivitamin that includes 150 mcg/day iodine (13).

Key Nutrients You Might Want to Include

Not Everyone Needs An Iron Supplement

Iron is a key mineral that aids in red blood cells delivering oxygen to the fetus and is important for preventing iron deficiency anemia during pregnancy. However, iron supplements are arguably hard on the digestive system, causing issues such as constipation, bloating, abdominal pain, etc.  The adult groups that are at increased risk for iron deficiency include those with a history of heavy menstrual cycles, gastrointestinal disease, and those who follow a vegetarian or vegan diet. To avoid unnecessary GI distress, iron levels should be assessed routinely via blood work and supplemented appropriately.

What about DHA?

Docosahexaenoic acid (DHA) is an omega-3 fatty acid. DHA during pregnancy plays a key role in brain and vision development.

The recommended intake of DHA during pregnancy is 200 mg/day from either diet and/or supplementation (14). If an individual consumes cold water, fatty fish 2-3x/week, they likely do not need an additional DHA supplement, however this should be reassessed throughout pregnancy to account for possible changes in intake. 

Also Look For

  • Vitamin A – An important nutrient for cell growth and differentiation, bone and teeth development, vision, and the immune system.
  • Vitamin B1 (Thiamin) – Supportive of the nervous system and aids in nutrient metabolism and energy production.
  • Vitamin B2 (Riboflavin) – Supports growth of baby’s bones, muscles, and nerves in addition to supporting healthy blood pressure.
  • Vitamin B3 (Niacin) –  Important for baby’s brain and nervous system development and may also ease nausea during pregnancy.
  • Vitamin B5 (Pantothenic acid) – Important for hormone synthesis which is especially crucial during pregnancy.
  • Vitamin B6 (Pyridoxine) – Aids in brain and nervous system development and red blood cell synthesis. It may also help reduce nausea during pregnancy.
  • Vitamin B7 (Biotin) – Important for nutrient metabolism and energy production with increased needs during pregnancy due to the increased metabolic demand.
  • Vitamin B12 (Cobalamin) – Supports neural tube formation and is associated with baby’s long-term motor development. This nutrient is especially important for vegetarians as it is found primarily in animal products.
  • Calcium – An important mineral for supporting bone and teeth development as well as muscle function. Pregnant females should be getting 1000 mg/day from diet and supplements. Take into account the intake of calcium-rich foods in an individual’s diet and supplement accordingly.
  • Magnesium – Supportive of blood pressure, sleep, and mood during pregnancy. There are many different forms of magnesium that can also impact bowel movements so choose an appropriate form based on an individual’s needs and be conscious of the upper limit of 350 mg/day.
  • Selenium – A powerful antioxidant which also plays a key role in thyroid hormone synthesis.
  • Zinc – Important for nutrient metabolism, cell growth, and the production of insulin.

Final Thoughts

Choosing a prenatal supplement regimen can be a daunting task given all the different options available and variability among each individuals nutrient needs. At the end of the day, recommendations for supplements should be tailored to an individual’s typical intake, medical history, lifestyle, and budget. There may not be a “perfect” prenatal multivitamin for every individual so focus on the key nutrients to look out for and supplement additional nutrients as needed. Working with a registered dietitian during this period can be especially helpful for providing targeted and appropriate supplement recommendations alongside dietary and lifestyle changes. Don’t hesitate to refer patients out to a prenatal nutrition expert to provide individualized nutrition care!

Erika Weber, MS, RD, is a licensed dietitian, trained chef, and founder of Cultivated Nutrition, PLLC. She specializes in fertility, pregnancy, postpartum, and pediatric nutrition. Erika is passionate about providing non-diet and weight-inclusive nutrition counseling to help people eliminate the stress around food and feel fully nourished wherever they’re at in their reproductive journey.

Website: www.cultivated-nutrition.com 
Instagram: @cultivatednutrition
Phone: (206) 395-9020


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