When should I start taking a prenatal vitamin?

When should you start taking prenatals? Before conception? After? What time of day should you take them? Read our detailed guide and find out.

By Dr. Mare Mbaye, MD, Natalist

When to start taking prenatal vitamins

Most women are aware that prenatal vitamins are an important part of a healthy pregnancy. What a lot of them don’t know, is that they should be taking them before conceiving. In fact, according to the Centers for Disease Control & Prevention (CDC), all women between ages 15 and 45 should be taking 400 micrograms (mcg) of folic acid daily — whether that’s in the form of a prenatal vitamin or some other supplement is up to you. That recommendation isn’t just from the CDC either. The American College of Obstetricians and Gynecologists (ACOG) also recommends folic acid supplementation to any woman who may become pregnant.

The main reason for this is due to the large number of unintended pregnancies that occur. A study published in 2016 revealed that in the US, a staggering 45% of pregnancies are unplanned. The window during which folic acid supplementation is most important is in the first 21 to 28 days after conception, which is way before many of these pregnancies are recognized. It’s no wonder this recommendation was made as a precaution of sorts. {Now, I will pause a moment here to say that if you are a reproductive age woman who is not trying to get pregnant and is on reliable birth control (sorry, condoms don’t count), then this recommendation isn’t necessarily applicable.}

Why are those first three to four weeks of pregnancy so important? The neural tube is the precursor in the embryo that eventually becomes the brain, spine, and spinal cord in the fetus later on in the pregnancy. Neural tube defects like spina bifida (a defect at the base of the spine) and anencephaly (a defect with the brain) occur when there is an issue with the neural tube closing like it is supposed to. Neural tube closure is usually done by the 28th day after conception — which, if the pregnancy wasn’t planned, is likely well before a woman knows that she’s pregnant. As the most common major malformation of the central nervous system, this is an important risk to consider and try to prevent.

Like most things in life, taking folic acid isn’t a guarantee. However, several clinical trials (you can read more about them here, here, and here) have shown that adequate folic acid consumption by women around the time of conception prevents a substantial proportion of neural tube defects.

The other reason why doctors recommend folic acid supplementation before becoming pregnant is because folic acid is a water-soluble vitamin, meaning you pee out any excess that you don’t need. Your body therefore can’t shore up any extra amount to be used on a rainy day. As a result, it’s good to have a regular intake of folic acid around the time of conception.

The other nutrients in prenatal vitamins aren’t quite as time sensitive so I won’t delve into them here, but you can check out this article to learn more.

So you might be wondering, what happens if I’m already pregnant? Is it too late to start taking a prenatal? The answer is no. The recommendation is to take prenatal vitamins as soon as you know you’re pregnant and throughout the remainder of your pregnancy. Pregnancy is not an easy road (as much as TV shows and movies try to make it seem so), and it takes a toll on the body. A pregnant woman simply requires higher amounts of certain nutrients while supporting the developing fetus. This makes a lot of sense when you think about the fact that the body is suddenly tasked with not only providing for mom’s body, but also for a whole new body that literally started from scratch. It’s pretty amazing, right? The best way we have to help the body out is to provide it with the nutrients it needs, in the right amounts.

Prenatals after pregnancy and during breastfeeding

Additionally, many providers recommend that women continue taking a prenatal vitamin even during the postpartum period. Surprisingly, there is no universal recommendation for exactly when to stop taking a prenatal vitamin. While all agree that vitamin D and iron supplementation postnatally is very important, there is no agreement on folic acid supplementation. The World Health Organization (WHO) does suggest continuing prenatal vitamins for as long as you breastfeed, and the ACOG notes that this is a common recommendation by OBGYNs.

Taking prenatal vitamins while breastfeeding is thought to be helpful because it ensures you’re getting the essential vitamins and minerals you need. All the necessary nutrients can be obtained from food if you’re eating a well-balanced diet — but let’s be real, that can be tough when you’re not only taking care of a newborn, but also a home and a career. A daily prenatal vitamin bridges any nutritional gaps that may exist in your diet while allowing you to worry about one less thing in your busy day.

According to a study published in 2012, there are significant benefits to continuing to take a prenatal through breastfeeding — specifically due to DHA, folate, vitamin D, and iodine. In the study, continued supplementation through the breastfeeding period led to better visual, cognitive, and motor development in the infant. The simple theory here is that a breastfed baby is getting all its nutrients from breastmilk during this time, which means the nutrient intake in mom translates to the nutrient intake in the baby.

What if you’re not breastfeeding? In that case, a prenatal vitamin isn’t necessary. A regular adult multivitamin is still a good idea, but it’s for your nutrition and not the baby’s in this case.

The best time of day to take your prenatal

Now that we’ve established why prenatals are so important to take — before, during and sometimes after pregnancy — let’s talk about when to take it on a daily basis.

The short answer is: whenever you’re the most likely to remember to take it! There’s no best “time” to take a prenatal vitamin in general, but that doesn’t mean there may not be a specific time that’s best for each woman. For some, it may be in the mornings with breakfast, while for others it may be with dinner or at bedtime. Certainly don’t worry about a particular time of day being best for absorption; your body absorbs nutrients from what you take in all day, everyday.

If you have any questions or concerns about starting a prenatal vitamin, running it by your provider is always a good idea. And especially if you have no idea where to begin the search for the right prenatal vitamin for you, a trusted provider can be a great resource to rely on.

Learn more at Natalist.com. Sign up for early access to receive resources and updates.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store