If you are planning a pregnancy or already expecting, you have probably been told to start a prenatal vitamin. What often gets missed is that many of those formulas do not contain nearly enough Vitamin D — and for Canadians especially, that gap matters more than most people realise.
Vitamin D is one of the most important nutrients during pregnancy, and one of the most commonly overlooked when it comes to dosage. This post breaks down what Vitamin D actually does before and during pregnancy, how much you likely need, and what to look for in your prenatal supplement.
Why Does Vitamin D Matter So Much During Pregnancy?
Vitamin D plays a direct role in your baby's bone and teeth development. The reason comes down to how your body handles calcium: Vitamin D is what allows your body to absorb and use calcium properly. Even if you are eating calcium-rich foods every day, low Vitamin D levels can limit how much of that calcium actually reaches your growing baby.
Beyond bone development, Vitamin D supports your immune system, your mood, and healthy cell division — all of which are working harder than usual during pregnancy. Your placenta also contains Vitamin D receptors throughout, which gives you a sense of how involved this nutrient is from the very start. To understand how Vitamin D works in the body more broadly, our complete Vitamin D guide is a good place to start.
What Happens If Your Vitamin D Is Low When You Are Pregnant?
Many Canadians are already walking into pregnancy with low Vitamin D levels. Because of our northern climate, we have limited opportunity to produce Vitamin D from sunlight for much of the year — and diet alone rarely fills the gap. Health Canada recognises that most Canadians do not get enough Vitamin D from food sources alone, which is why supplementation is so commonly recommended.
Low Vitamin D during pregnancy has been linked in research to fatigue, low mood, and reduced immune resilience — things that are already challenging enough when you are pregnant. If you were deficient before conceiving, a standard prenatal dose may not be enough to bring your levels up to where they need to be. You can read more about the general warning signs in our post on Vitamin D deficiency symptoms.
How Much Vitamin D Do You Need Before and During Pregnancy?
Health Canada's official recommendation is 600 IU of Vitamin D per day for pregnant women. That said, many practitioners — especially those working in Canadian climates — consider this a conservative baseline. It is not uncommon for healthcare providers to suggest anywhere from 1,000 to 2,000 IU daily for pregnant women, particularly those who spend limited time outdoors or who were deficient going in.
The most reliable way to know where you stand is a simple blood test. If you are in the preconception phase, asking your doctor to check your Vitamin D level alongside your other prenatal bloodwork is a smart move. From there, you and your provider can figure out the right amount for you specifically.
Does Your Prenatal Vitamin Have Enough Vitamin D?
This is worth looking into. Many prenatal vitamins contain between 400 and 600 IU of Vitamin D, which meets the minimum guideline but may fall short if you are starting from a low baseline or living somewhere with limited sun exposure — which describes most of Canada for a good chunk of the year.
When you check your prenatal label, look specifically for Vitamin D3 (cholecalciferol). This is the form your body produces naturally from sunlight and absorbs most effectively. If your formula contains D2 (ergocalciferol) or a low dose of D3, it may be worth discussing a separate Vitamin D supplement with your healthcare provider. Our post on supplements to take with Vitamin D covers how to build a smart supplement stack without over-supplementing.
The Best Time to Start Supplementing with Vitamin D
The best time to start is before you get pregnant. Vitamin D is fat-soluble, which means it takes time to build up to a meaningful level in your body. Starting your prenatal vitamin — with adequate Vitamin D included — at least three months before conception gives your body the runway it needs.
If you are already pregnant and have not been paying close attention to your Vitamin D intake, that is okay. It is not too late to start, and your levels can improve at any stage. The important thing is to act on it rather than assume your prenatal is covering everything. When in doubt, speak with your healthcare provider about testing your levels.
Choosing the Right Prenatal Supplement
Not all prenatal vitamins are built the same. What you want to look for is a formula that includes a meaningful dose of Vitamin D3, along with the other foundational nutrients for pregnancy like folate, iron, and choline — in forms your body can actually absorb.
Two of the prenatal formulas we carry and trust at Wellness Market are Thorne Basic Prenatal and NFH Prenatal SAP. Both are professional-grade formulas that go beyond the bare minimum, with well-absorbed nutrient forms and doses that reflect what current research supports. If you are not sure which is the right fit for you, our team is always happy to help you compare them.
And if you want to add a separate Vitamin D supplement on top of your prenatal — which many practitioners recommend, especially through the fall and winter — you can explore our Vitamin D collection to find the right form and dose.
Frequently Asked Questions
Q: Can I take extra Vitamin D on top of my prenatal vitamin while pregnant?
Many people do, and it is often recommended — particularly in Canada, where sun exposure is limited for much of the year. Because Vitamin D is fat-soluble and can accumulate in the body, it is best to check the dose in your current prenatal and speak with your healthcare provider before adding a separate supplement.
Q: What is the difference between Vitamin D2 and D3 in prenatal vitamins?
Vitamin D3 (cholecalciferol) is the form your body produces naturally from sunlight and is generally more effective at raising blood levels. Vitamin D2 (ergocalciferol) comes from plant sources and tends to be absorbed less efficiently. When choosing a prenatal vitamin, look for D3 on the label.
Q: When should I start taking a prenatal vitamin with Vitamin D?
Ideally, at least three months before you plan to conceive. This gives your body time to build up Vitamin D and ensures other key nutrients like folate are in place before conception. If you are already pregnant, starting now is still worthwhile — it is never too late to support your levels.
Q: Is Vitamin D deficiency common in pregnant Canadians?
It is more common than many people realise. Canada's northern latitude means limited sun exposure for much of the year, and the demand for Vitamin D increases during pregnancy. This combination makes it especially important for expecting mothers to pay attention to their levels rather than assume food and minimal sun exposure are enough.
The Bottom Line
Vitamin D tends to fly under the radar during pregnancy — many women assume their prenatal covers it, and sometimes it does, but often not at the level that actually supports a Canadian lifestyle. The good news is that checking your levels is simple, choosing a quality prenatal is straightforward once you know what to look for, and small adjustments to your routine can make a meaningful difference for both you and your baby.
Browse our prenatal multivitamin collection or Shop vitamin D supplements to find a formula that works for you, or reach out to our team — we are here to help.
