Everything You Need to Know About Prenatal Vitamins

Jul 21

10 min read

Updated: Jul 23

This post was collaborated with Maddie Regev, a nutraceutical expert, and director of product research, development, and education for Nutra Axis Labs. The following is for informational purposes only.

The Purpose of Prenatal Vitamins

Pregnancy is one of the few times in life when your nutrient needs increase significantly. You’re not just supporting your own health - you’re growing an entire new human, building a placenta, expanding tissues, increasing your blood volume by up to 40-50%, and preparing your body for breastfeeding. That’s a LOT to ask of your body, and all of it requires nutrients.

Is it possible to get everything you need from food vs taking a prenatal?

In theory, yes. But in reality, this would be very difficult. We see the largest increase in nutrient demand for iron, folate, iodine, choline, vitamin D, zinc, and several b-vitamins during pregnancy. A healthy diet should always be the foundation, but many women experience nausea, vomiting, food aversions, reduced appetite and digestive changes which makes getting the right things more challenging.

A woman would need to consistently eat a well-balanced, nutrient dense diet (and lots of it) every single day while also absorbing the nutrients efficiently. Pregnancy often makes that much harder than it sounds.

Let’s look at iron, for example. Between blood volume increase, baby building their blood supply, and placenta needs, iron requirements increase to 27mg per day.

While it’s possible to meet this need through a carefully planned diet, consistently getting 27mg of iron from food alone can be difficult. To provide roughly 27mg of iron from a single food, you’d need to eat around 8-10 ounces of cooked beef liver (which is not recommended in pregnancy because of its extremely high preformed vitamin A content), about 4-5 cups of cooked spinach (and because this is non-heme iron, it’s generally less readily absorbed than the iron in meat), roughly 1.5-3 pounds of cooked beef (depending on the cut), or several pounds of cooked chicken breast.

Of course, no one is expected to get all of their iron from a single food. Iron intake comes from a variety of foods throughout the day, and pairing plant-based sources of non-heme iron with vitamin C can help enhance absorption. This comparison is simply meant to illustrate why consistently meeting increased iron needs through diet alone can be challenging during pregnancy (and why iron is one of the nutrients that may require extra attention).

Food is Incredibly Important

This doesn't mean food isn't important, it absolutely is! Whole foods provide fiber, protein, healthy fats, antioxidants and THOUSANDS of beneficial compounds that supplements can't replace.

A prenatal is simply intended to complement a healthy diet by helping to ensure that key nutrients are constantly and consistently available during a time where mom and baby both have increased nutrient demands. Think of it as nutritional insurance rather than a substitute for eating well.

What are the most important things to look for in a prenatal?

There are two common trends to be cautious of when it comes to prenatals:

First, a brand that claims to be more minimal, but ends up lacking on the nutrients that matter.

Second, a brand that has a supplement facts panel stacked full of nutrients, but lacks adequate dosing or has such a large serving size it becomes unrealistic to supplement.

The question comes down to a couple things:

Are the nutrient forms appropriate? Specifically:
1. Folate as methylated folate (or for individuals sensitive to methyl donors, folinic acid
  1. Folic acid is the synthetic form of folate found in many conventional prenatal vitamins and fortified foods like cereals, breads, and pasta. Before your body can use it, it has to go through several enzymatic steps to become L-5-MTHF (methylfolate), the active form that circulates in the bloodstream. Most people convert folic acid just fine, but some individuals with certain genetic or metabolic differences have a difficult time.
  2. Methylfolate is the biologically active form of folate, so it doesn't require conversion by the MTHFR enzyme before the body can use it. Because it's already active, many practitioner-grade prenatals now use methylfolate instead of folic acid.
  3. Then there's folinic acid (also called reduced folate), which many people have never heard of. It sits metabolically between folic acid and methylfolate. Unlike folic acid, it doesn't require the initial reduction step, but it still must be converted into methylfolate before it can participate in methylation and other folate-dependent processes.
2. B12 as methylcobalamin (not cyanocobalamin)
  1. Cyanocobalamin is the most common form of vitamin B12 used in supplements because it's stable, well studied, and effective. Before your body can use it, it removes a tiny, clinically insignificant cyanide group and converts it into the forms your body actually uses: methylcobalamin and adenosylcobalamin. Methylcobalamin is already in one of those active forms, so it doesn't need that conversion step before your body can put it to work.
3. We personally prefer other active B-Vitamin forms, as well, such as B6 as Pyridoxal-5-Phosphate (P5P), B2 as Riboflavin-5-Phosphate, B1 as benfotiamine or thiamine pyrophosphate
  1. The same idea applies here. These are forms of the vitamin that are already closer to the form your body actually uses. For example, vitamin B6 is often listed as pyridoxine HCl, which first has to be converted by your body into pyridoxal-5-phosphate (P-5-P), the active form. Once it's in this form, your body can use it to support things like brain function, protein metabolism, and many other important processes.
4. Tolerable form of iron like bisglycinate chelate
5. Higher bioavailability magnesium like magnesium glycinate (reduced risk of GI discomfort)

Are the doses meaningful?

Some prenatals include omega-3s and choline, but often in doses too low to meaningfully contribute to pregnancy needs. For example, 50 mg of choline when the recommended intake is 450 mg per day isn’t moving the needle much. The same can be true for small amounts of omega-3s, especially DHA.

At a certain point, these amounts feel more like label dressing than meaningful nutritional support. And while high Daily Value percentages can look alarming, remember that the amount on the label isn’t necessarily the amount your body absorbs and uses. Absorption varies, and nutrient needs increase significantly during pregnancy.

To keep this guide simple, we aren’t evaluating products on omega-3 content unless it’s contained in the formula. Pregnant women should be supplementing omega-3’s in addition to their prenatals.

The “4 Types” of Prenatals

You'll often see prenatal vitamins marketed as whole food, naturally derived, synthetic, or organ-based. While these descriptions can sound important, they don't necessarily predict how effective a prenatal will be.

Whole Food Prenatals

Whole food prenatals are made using nutrients derived from concentrated fruits, vegetables, or yeast. Many people prefer these products because they feel less processed. "Whole food" doesn't automatically mean better absorbed or more effective, and can often mean greater pill load (which is a small price to pay if this feels like an important factor for someone)!

Naturally Derived

Naturally derived vitamins are extracted from natural sources, such as vitamin E from sunflower oil or vitamin D from lanolin (sheep's wool). These ingredients can be excellent choices, although the term itself isn't tightly regulated, so just double check the label if this one is a big consideration for you.

Synthetic Vitamins

Synthetic vitamins get an unfair reputation, as many synthetic vitamins are chemically identical to the vitamins naturally found in foods. In fact, much of the research supporting prenatal supplementation has been conducted using these forms. More important than whether a vitamin is synthetic is whether it's an appropriate and bioavailable form. For example, choosing methylfolate instead of folic acid may be beneficial for many individuals.

Organ-Based

Organ-based prenatals typically rely on ingredients like beef liver to naturally provide nutrients such as iron, vitamin A, B vitamins, and choline. While these products can be nutrient-dense, nutrient amounts vary naturally from batch to batch, and many still require additional supplementation to meet pregnancy recommendations. Vitamin A also deserves special attention because excessive preformed vitamin A intake during pregnancy can be harmful, making formulation quality especially important.

Ultimately, there isn't one category that's universally "best." The overall formulation, nutrient forms, dosing, quality testing, and how well the prenatal meets an individual's needs are far more important than the marketing label on the front of the bottle.

A Note on Iron & Omega 3s

Many high-quality prenatals intentionally omit iron. While iron can be included in a prenatal, absorption may be reduced when it's combined with higher doses of calcium and magnesium. Separating iron allows for more personalized dosing, gives you the flexibility to choose a well-tolerated form, and may help optimize absorption when a prenatal already contains meaningful amounts of other minerals.

Many also don’t include omega 3s. Although they can be included safely in a prenatal when properly formulated, omega-3s are delicate and require careful encapsulation and packaging to help minimize oxidation. Many prenatals also include DHA in doses that are too low to meaningfully support pregnancy. Taking a separate, high-quality omega-3 allows for both an effective dose and greater confidence in the product's quality.

A Breakdown of Some Popular Brands

There are a lot of great prenatal options, and there isn’t necessarily one “best” choice for everyone. The biggest thing to keep in mind is that you may need to mix and match products based on your individual needs, diet, labs, and stage of pregnancy or postpartum.

Personally, during pregnancy and postpartum, we take a prenatal, a high-DHA fish oil that also contains EPA, and a probiotic that we switch up throughout pregnancy. We'll also add heme iron if our prenatal doesn’t contain iron or my labs indicate we need additional support. From there, we continue to reevaluate and adjust my supplement routine as pregnancy progresses.

Fig (Synthetic) This prenatal stands out for its high choline content, reflecting the growing body of research on the importance of adequate choline intake during pregnancy. It does not contain iron, but provides a substantial dose of magnesium in the glycinate form (350 mg) without making the overall pill load excessively large.

Needed (Synthetic ) Strong formulation overall, with optimal dosing for many nutrients. A few things to note: it does not contain iron, the choline dose is lower than many modern targets, and in my experience working with this product, the higher B-vitamin doses may cause headaches for some people.

code: ALEX20 for $$ off

FullWell (Synthetic) One of the more nutritionally comprehensive prenatals on the market, with thoughtful dosing across many key pregnancy nutrients. The omission of iron and the high daily capsule burden are the main considerations.

Seeking Health Optimal Prenatal (Mixed, but Primarily Synthetic) This one includes highly bioavailable forms of minerals and active B vitamins, along with the full recommended daily intake of choline for pregnancy. Iron is not included and may need to be supplemented separately based on individual needs. This omission may be intentional given the higher amounts of calcium and magnesium in the formula, which can interfere with iron absorption when taken together.

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We Heart Nutrition (Natural + Synthetic) A well-balanced prenatal that includes a patented form of choline, a substantial dose of vitamin D, active B vitamins, adequate mineral support, and vitamin K2 at a researched dose. Iron is not included, so individual iron needs should be evaluated and supplemented separately when appropriate

Thorne (Synthetic) A pretty comprehensive prenatal that includes active B vitamins, Albion minerals for enhanced bioavailability, and an adequate amount of iron. It is lower in choline, calcium, and magnesium, though the lower levels of calcium and magnesium may be intentional, as higher amounts can compete with iron for absorption when taken together.

Just Ingredients (Whole + Naturally Derived) This is a combination of whole foods and likely naturally derived. This prenatal offers a nice variety of nutrients, including an adequate amount of folate. One thing to note is that many of the B vitamins are dosed around 100% of the Daily Value, while many prenatal formulations provide higher amounts to account for increased needs and differences in absorption. It also does not contain iron, and vitamin D is on the lower side (both of which can easily be supplemented separately). Overall, this is a solid option for women looking for a more whole-food-based prenatal, with the understanding that the formula does contain some isolated nutrients and is not exclusively whole-food derived.

code: ALEXK for $$ off

Ritual (Synthetic) A simple prenatal with a low capsule burden, but nutritionally lighter than I would prefer. The simplicity of the formula can leave meaningful nutrient gaps if used alone. While it does include omega-3s, the dose is relatively low, so additional omega-3 intake may be beneficial. Additional iron and choline may also be needed depending on diet, labs, and individual needs.

Perelel (natural and synthetic) A simplified prenatal when evaluated on its own. While the packets provide additional support through complementary supplements, the prenatal itself is nutritionally lighter than I would prefer for pregnancy, particularly when it comes to mineral support, choline, and overall formulation depth.

Bloom (Birthright) (Organ based) - I know products like this have very passionate supporters, and there are certainly aspects of the philosophy that I appreciate. However, when evaluating it against current evidence and pregnancy nutrient recommendations, I don’t think it should be considered a complete prenatal on its own.

While organs naturally contain many important nutrients, the exact amounts can vary depending on the animal, its diet, season, and processing methods. Without standardized amounts of each nutrient listed, it can be difficult to know whether someone is actually meeting pregnancy recommendations.

Choline is one example. Beef liver is naturally a good source of choline, but Bloom does not disclose the amount of choline provided by the finished product (or even the exact amount of liver contained in the liver and bone marrow blend). Drying liver removes water and concentrates its nutrients by weight, but without testing and disclosing the choline content of the finished product, there is no way to know how meaningfully it contributes toward the 450 mg of choline recommended daily during pregnancy.

If someone loves the philosophy behind an organ-based prenatal, I wouldn’t necessarily discourage them from using it. However, I also wouldn’t recommend relying on it as the sole source of prenatal nutrition without carefully reviewing the rest of their diet and discussing whether additional supplementation may be needed with their healthcare provider.

The Natural Minded Mama

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