Think All Prenatal Vitamins Are The Same?

Picking a prenatal should be simple, but between the endless aisle of supplements to choose from, the glossy packaging, advice from friends and endless Google searches about maternity care, it's easy to feel completely lost.

While it would be convenient if every prenatal vitamin were the same, the truth is that dosages, formulas and ingredients vary from brand to brand. This can affect how your body absorbs the nutrients and even which nutrients you and your baby receive.

So, if you’re ready to cut through the confusion, here’s everything you need to know: what to look for on the label, how to compare brands, and expert-backed tips for choosing the one that truly fits your pregnancy journey.

How prenatal vitamins differ

Prenatal vitamins share the same goal—to improve maternal health—but they can vary widely in ingredients, nutrient amounts and formulations. Choosing the wrong one could leave you missing key nutrients, says Dr. Prati Sharma, MD, FACOG, an obstetrician-gynecologist, reproductive endocrinology and infertility specialist, and advisor with Bird & Be, a company focused on fertility and maternal health care supplements.

“For example, adequate folic acid and DHA are crucial, yet sometimes absent,” she explains. “And with iron—essential for building stores before pregnancy as blood volume doubles—the form matters. Ferrous bisglycinate is often gentler on sensitive stomachs than fumarate or sulfate.”

Other nutrients, such as choline for fetal brain development and iodine for thyroid health, are often missing from some prenatals, even though both are especially important during pregnancy. That’s why Sharma recommends choosing a prenatal tailored to your needs.

“Individual requirements vary based on factors like age, underlying health conditions and genetics,” Sharma says. “We all process nutrients differently, and some women have a harder time converting them into absorbable forms. For example, women with MTHFR gene mutations—a risk factor for folate deficiency, which can compromise fetal health if not addressed—cannot effectively process folic acid and require methylated folate instead.”

Key ingredients

The ingredients and the amounts of each in prenatal vitamins can vary more than you might expect. Sharma recommends seeking prenatal vitamins that offer a balance of key nutrients like folic acid, iron, calcium, and vitamin D to support your overall health and your baby’s development. Each nutrient plays an essential role in supporting pregnancy and reducing the risk of complications.

She says that folate helps prevent neural tube defects, iron supports red blood cell production and oxygen transport as blood volume increases, and vitamin D works with calcium to build strong bones and support immune health. “I also recommend DHA, an omega-3 fatty acid that’s crucial for fetal brain, mental health, nervous system and eye development, along with iodine, zinc, and selenium for thyroid support. These nutrients are vital during pregnancy, yet often missing from many formulations.”

Still, ticking off ingredients isn’t quite enough. The right amounts matter just as much as the ingredients themselves. “With DHA, for example, you might see 50 to 100 milligrams on the label, but closer to 200 to 300 milligrams daily is ideal for brain development," Sharma explains. "That’s why I always encourage patients to check both the ingredients and their actual amounts.”

Formulations and absorption

Prenatal vitamins come in many forms, including pills, gummies and liquid supplements. As you consider your options, remember that each type has its own set of pros and cons. It's always a good idea to consult your physician before starting any new supplement.

The specific formulation of a prenatal vitamin can affect how well your body absorbs the nutrients. For example, a 2023 study published in the Journal of Family Medicine and Primary Care found that taking iron and calcium together can reduce the absorption of both. The study also highlighted that combining multiple supplements may interfere with absorption or even cause negative effects if not taken properly.

When choosing prenatal vitamins, look out for common additives and allergens you may want to avoid. These include added sugars, artificial colours, flavours, preservatives, soy, dairy, eggs, and, for those with sensitivities, corn derivatives. Reviewing the ingredients can help you select a supplement that best meets your needs.

Special considerations and personalized needs

Every pregnancy is unique, bringing its own mix of needs, preferences and challenges. That’s why it is so important to choose prenatal vitamins that fit your body and lifestyle instead of settling for a one-size-fits-all blend, says Keira Saucerman, MS, NBC-HWC, a certified health coach, integrative nutritionist, and Lead Health Coach and Director of Operations at Sarana Health.

“Everyone’s metabolic health is unique because every person is unique,” Saucerman explains. “Your lifestyle choices, your food choices, and even your microbiome’s ability to digest and absorb nutrients all vary from one person to the next. This means that throwing a generic label on what prenatal vitamins someone should take is not as effective as understanding what they need on a cellular level.”

It is not just lifestyle that matters. “Medical conditions—including high blood pressure—and medications could affect nutrient absorption before conception,” she cautions. “This increases the risk for pregnancy complications if not properly addressed with personalized prenatal supplementation."

Diet also plays a big role. “Dietary restrictions can be a key factor in nutrient insufficiency, which plays a pivotal role in determining prenatal supplementation—and can ultimately affect birth outcomes," Saucerman notes. “For instance, vegans and vegetarians likely will not be getting proper Vitamin B12 through diet alone since it is mostly found in animal proteins, and it is not found in most generic prenatal vitamins.”

Understanding Canadian regulations and recommendations

Canada has distinct guidelines for prenatal vitamins, aimed at improving access to safe and effective supplementation. As Sharma explains, "Supplements here are classified as Natural Health Products (NHPs), which means Health Canada must review and approve the formula, the research backing it, and even the marketing claims. Once approved, products get a Natural Health Product Number (NPN) that must appear on the label.”

Once a prenatal vitamin is approved, its contents are guided by evidence-based nutrient recommendations. In particular, folic acid is a cornerstone of prenatal supplementation. “Health Canada and the Society of Obstetricians and Gynaecologists of Canada (SOGC) recommend that anyone who could become pregnant take 400 mcg DFE of folic acid daily, increasing to 600 mcg once pregnant,” Sharma says. “For those with a history of a neural tube defect–affected pregnancy, the dose jumps to 4,000 mcg (4 mg) starting at least a month before conception and continuing through the first trimester, under medical supervision.”

Iron is another nutrient getting more attention in recent years. Until recently, low ferritin levels—defined as <10 or <15 μg/L, depending on the lab—signalled deficiency. “Ontario’s updated standard is <30 μg/L,” notes Sharma. “That means more people may now be considered deficient and may require higher, more absorbable forms of iron in their prenatal.”

While folic acid and iron are well known, choline often flies under the radar, despite being essential for both brain development and neural tube formation. “Health Canada recommends 450 mg per day during pregnancy, but many prenatals skip it entirely,” Sharma warns. "Since it’s difficult to reach that target through diet alone, supplementation can help fill the gap. For perspective, two eggs give you roughly 300 mg."

What's an NPN number and why are they important?

In Canada, natural health products (NHPs) can’t be sold without an official identification number: an NPN (Natural Product Number) or, for drugs, a DIN. This requirement isn't just bureaucratic red tape. As Sharma explains, an NPN means that Health Canada has reviewed everything, from the formula and dosage to pregnancy safety, and confirmed that any health claims, such as “supports neural tube health,” are backed by credible evidence.

That verification matters. Without an NPN, you’re essentially relying on the manufacturer’s word for it, which can be risky. “There’s no guarantee the nutrients listed are present, that the product is free from contamination, or that the claims are even approved for use here,” Sharma cautions.

Fortunately, checking out a product's legitimacy is straightforward. "Look for the eight-digit NPN printed right on the label, then search it on Health Canada’s Licensed Natural Health Products Database," instructs Sharma. "You’ll get a clear read on what it’s licensed for, the safety info, and the precise amounts of each ingredient."

How to choose the right prenatal vitamin for you

Choosing the right prenatal vitamin doesn’t have to feel overwhelming. According to Ayla Brammer, MS, RD, LDN, of FullWell, the first thing you should do is check out who’s actually behind the formulation. “Opt for vitamins that are formulated by credentialed professionals, like registered dietitians, who rely on evidence-based science,” she suggests.

Next, turn your attention to the label and make sure you’re getting all the essentials—no more, no less. “A lot of prenatal brands skip crucial ingredients like magnesium, choline, or calcium simply because they’re bulky and require more capsules,” Brammer explains. She also notes that certain nutrients, such as iron and DHA/EPA, are best supplemented separately, rather than lumped into one pill, to sidestep absorption problems or unwanted oxidation.

And don’t overlook the fine print: Brammer recommends opting for brands that go the extra mile with independent, third-party testing for contaminants, potency, and allergens, and that make Certificates of Analysis accessible to customers. Finally, try to find a prenatal with active forms of nutrients like B12 and B6, plus chelated minerals (think magnesium), for better absorption and gentler digestion.

The bottom line

Not two prenatal vitamins offer the same benefits, so choosing the right one is essential for your health. By relying on expert-backed information and working closely with your healthcare provider, you can make confident, personalized decisions that support a healthy pregnancy.

Regular communication with your healthcare team allows you to respond to your changing needs—whether it’s switching to a prenatal vitamin with more iron or adjusting your diet to manage symptoms and nutrient gaps, even during the postpartum period. By having these ongoing conversations, you can reduce the risk of complications (such as pregnancy-related deaths) and support your health in the long term.

Experts

• Dr. Prati Sharma, MD, FACOG, is an obstetrician-gynecologist, reproductive endocrinology and infertility specialist, and advisor with Bird & Be, a company focused on fertility and maternal health care supplements.
• Keira Saucerman, MS, NBC-HWC, is a certified health coach, integrative nutritionist, and Lead Health Coach and Director of Operations at Sarana Health, a health and wellness company.
• Ayla Brammer, MS, RD, LDN, is a registered dietitian with FullWell, a company focused on fertility wellness through evidence-based, high-quality supplements.