You just received a positive pregnancy test and are filled with emotions. You’re excited, but also wondering if you should have been taking prenatal vitamins already. Or maybe you’re not pregnant yet, but planning to be and wondering where a prenatal fits in. 

Starting prenatal vitamins at any stage will benefit you and your baby’s health. This guide covers when to start based on where you are right now, and how to choose the right one.

Key Takeaways

• The ideal time to start taking a prenatal vitamin is at least two to three months before you begin trying to conceive.
• If you’re already pregnant and haven’t started yet, it’s not too late. Starting a prenatal vitamin after a positive test is still recommended by Canadian health guidelines.
• Folic acid (also called folate) is an important nutrient in your prenatal vitamin. Low-risk individuals need 400 mcg daily starting before conception and continuing through the first 12 weeks of pregnancy.

When Should You Start Taking Prenatal Vitamins?

The Society of Obstetricians and Gynaecologists of Canada (SOGC) recommends starting a daily prenatal multivitamin at least two to three months before trying to conceive. This head start helps your body build up the tissue stores of pregnancy nutrients, especially folate, before they’re needed for early fetal development.

Women of childbearing age should consider taking a daily multivitamin with folic acid, even if they’re not trying to conceive. More than 50% of pregnancies in Canada are unplanned, so if you’re already taking a multivitamin, you’re not missing out on early fetal development vitamin needs if you do get pregnant. 

Is It Too Late If You’re Already Pregnant and Haven’t Started?

No. The SOGC still recommends starting a prenatal vitamin after a positive pregnancy test, noting that most neural tube defects happen in the first four weeks of gestation.

Some women don’t discover they’re pregnant until after that window has passed. Even if you missed the earliest days, your body and your growing baby still need a steady supply of nutrients, including iron, vitamin D, DHA, and calcium, for the rest of your pregnancy. 

Start as soon as you can after a positive test, and keep taking your prenatal consistently from there.

Browse prenatal vitamins at Well.ca and consult with your healthcare provider to select the right formula for where you are in your pregnancy journey.

Why Timing Matters: Folic Acid and Neural Tube Development

To understand why folic acid is important, you need to understand the basics of early fetal development: 

• Folic acid is the synthetic, highly stable form of folate, a B vitamin (B9) that your body uses for DNA synthesis and rapid cell division. 
• The neural tube is the embryonic structure that becomes your baby’s brain and spinal cord. 
• This tube closes within the first 28 days of gestation. That’s why it helps to have folic acid stores ready before you even know you’re pregnant.

When folate levels are too low during that four-week window, the neural tube may not close properly. This can lead to congenital disabilities, including anencephaly and spina bifida, a condition where part of the spinal cord doesn’t develop correctly. 

How Much Folic Acid Do You Need?

Your recommended dose of folic acid depends on your personal health history, but generally falls between 0.4 and 4 mg daily. The SOGC suggests folic acid dosages based on your risk level and how much you get from your diet.

Your healthcare provider can help you determine your risk level and ideal dosage. 

What happens if you don’t take prenatal vitamins before getting pregnant?

Not taking prenatal vitamins before getting pregnant doesn’t automatically put your pregnancy at higher risk. It does mean your body may have lower stores of nutrients like folate and iron right when they’re needed most, but starting a prenatal as soon as you find out you’re pregnant helps close that gap quickly. 

How to Choose and Take a Prenatal Vitamin

A good prenatal vitamin should include the nutrients that are hardest to get from diet alone during pregnancy: folic acid or methylfolate, iron, vitamin D, DHA (an omega-3 fatty acid), choline, vitamin B12, and calcium.

When shopping for a prenatal vitamin, look for these qualities:

• Is it third-party tested? In Canada, look for NSF, USP, or ISURA certification, which means an independent lab has confirmed what’s on the label matches what’s in the bottle, with no heavy metals or contaminants. 
• Check the nutrient form, not just the nutrient. Methylfolate absorbs better than synthetic folic acid, especially if you have MTHFR, and chelated iron (like iron bisglycinate) is gentler on your stomach than standard ferrous sulphate. 
• Watch for unnecessary fillers, especially if you’re breastfeeding. Additives and herbal ingredients, including artificial dyes, food allergens, and excessive iron, can pass into breastmilk. 

Take your prenatal with a meal to minimize nausea and improve absorption, particularly for iron. If the increased iron is making you constipated, ask your pharmacist or doctor about lower-iron formulas or splitting your dose.

Shop prenatal vitamins at Well.ca to browse third-party-tested options in a range of formats, including capsules, softgels, and gummies.

What to Avoid When Taking Prenatal Vitamins

Here are a few things to keep in mind when taking prenatal vitamins:

• Take it with food. Iron especially can cause nausea and cramping on an empty stomach.
• Don’t megadose. Vitamins A, D, and E are fat-soluble. That means more isn’t better, and too much can build up to toxic levels. Stick to the dose on the label unless your healthcare provider says otherwise.
• Consistency matters. Folic acid’s protective effect depends on taking it daily, especially in the first trimester.
• Watch your timing with coffee, tea, and high-fibre foods. They can block iron absorption, so take your prenatal two hours before or after them.
• Skip the social media advice. For dosage or safety questions, check Health Canada guidelines or talk to your doctor or a registered dietitian.

Note: This article serves as a guide to help you build your knowledge of prenatal vitamins and is not a substitute for medical advice. Your needs are unique, and dosage recommendations can change. Always discuss your prenatal vitamin and pregnancy care needs with your healthcare provider. 

Do You Need a Prenatal If You’re Not Trying to Conceive Yet?

You don’t need to wait until you’re actively trying to conceive. If there’s any chance you could become pregnant in the next year or two, starting a prenatal multivitamin now is reasonable.

Prenatal vitamins aren’t hormonal. Taking them won’t directly affect your menstrual cycle, but can still support good overall health. For some people, correcting an underlying micronutrient deficiency can indirectly support a more regular cycle.

For more on what to look for in a prenatal formula, check out our guide: Prenatals 101: Navigating the World of Prenatal Vitamins.

Taking Prenatal Vitamins After Birth

The postpartum period, which covers up to 12 months after delivery, is a time of physical (and psychological) recovery. Your nutritional needs are different from pregnancy, and your prenatal vitamins may not meet your new nutritional needs.

During pregnancy, your blood volume increases by 50%, and you need 27 to 45 mg of iron daily to support this expansion. After delivery, your iron needs drop to around 9 mg daily while breastfeeding because menstruation has temporarily stopped. A high-iron prenatal when you no longer need that much can cause constipation, cramping, and nausea.

Breastfeeding also increases your need for vitamin A, vitamin C, choline, vitamin B12, and vitamin D. Your prenatal formula may not have a high enough dosage, so this is where a postnatal can be more beneficial. Postnatal vitamins also directly affect the quality of your breastmilk. Water-soluble vitamins like B12 and choline pass into it, so low stores will impact its nutrient quality.

As Dr. Robert Thompson, DO, MS, CPE, FAAFP, Medical Contributor at Care Point Boston puts it, “A “good” postpartum vitamin isn’t necessarily a stronger prenatal; it is the formula that addresses the missing pieces in the patient’s diet, medical history and/or breastfeeding demands.”

Continue taking your postnatal vitamins as long as you’re breastfeeding, or until recommended by your doctor. Generally speaking, you’ll be taking these supplements as long as you’re breastfeeding. If you’re not breastfeeding, a postnatal formula or basic women’s multivitamin is recommended for six to eight weeks, sometimes up to three months, to support physical recovery and rebuild nutrient stores depleted during pregnancy.

Are you ready to find the right prenatal for where you are in your pregnancy? Discuss your nutrient needs with your doctor, then shop prenatal vitamins at Well.ca.

This article is for informational purposes only and is not a substitute for professional medical advice. Always talk to your healthcare provider before starting or changing any supplement routines.

FAQs on Prenatal Vitamins

How early in pregnancy should you start taking prenatal vitamins?

The SOGC recommends starting a daily prenatal multivitamin at least two to three months before you begin trying to conceive to build up nutrient stores for pregnancy. Starting earlier gives your body more time to prepare these stores, but you can still build them at any point in your pregnancy. 

When is it too late to start taking prenatal vitamins?

There’s no point in pregnancy where it’s too late to start taking prenatal vitamins. If you just found out you’re pregnant, visit your doctor and order prenatal vitamins as soon as you’re able.

Does taking prenatal vitamins help with irregular periods?

Prenatal vitamins won’t directly regulate your cycle the way hormonal therapies can. But if irregular periods are connected to a nutrient deficiency, filling those gaps with a quality multivitamin may support better overall reproductive health. If your periods are consistently irregular, that’s worth raising with your doctor to see if vitamin supplementation can help.