We started by compiling a list of all the over-the-counter vitamins we could find that are available from most major retailers, like Amazon, GNC, and Whole Foods. Our starting cohort of 71 brands contained both food-based vitamins (nutrients derived from food) and synthetic vitamins (nutrients created in a lab), since we wanted to find out if one was more beneficial than the other. (Spoiler alert: not really.) We didn’t include prescription prenatals in this review. As Dr. Brian Levine, practice director at the Colorado Center for Reproductive Medicine (CCRM) New York, says, “Most prescription brands don’t add that much, even though they’re a lot more expensive. The over-the-counter brands of the major pharmaceutical chains, those tend to be really good at a low price.” To start narrowing down our options, we talked to three doctors to determine what nutrients were most essential in a prenatal vitamin. All our top picks include: But picking a best required some more digging.
Any OB/GYN will tell you that folate (or its synthetic alter ego folic acid) is a hugely important part of a woman’s prenatal diet. Inadequate folate levels early in pregnancy can lead to neural tube defects, which sometimes result in infants being born with paralyzed legs or improperly formed skulls, among other problems. Folate exists naturally in leafy green vegetables (brussels sprouts have some of the highest folate levels of any food) as well as fruit, grains, beans, and some dairy products. Folic acid is also added to most breads, grains, pasta, and cereals manufactured in the US, following a 1998 government mandate aimed at improving general public health. But doctors and researchers widely agree that pregnant women and women trying to conceive should take extra folic acid in supplement form to make up for any dietary gaps. “Even among people who are actually pregnant, only about 60 percent are taking folate,” said Dr. Scott Sullivan, an associate professor at the Medical University of South Carolina.
“This is an instance where we can stop devastating, lifelong birth defects by just taking a vitamin — yet we fail.” We eliminated all vitamins that didn’t contain a minimum of 400 micrograms of folic acid, as recommended by the CDC. We also cut any that contained more than the CDC’s recommended tolerable upper limit for pregnant women — about 1,000 micrograms. While a baseline amount of folic acid is essential, very high amounts could cause stomach aches, sleep interruption, or (in rare case) seizures. This is one area where it’s fairly clear that most pregnant women benefit from a dietary supplement. A developing fetus uses vitamin D to grow strong, healthy bones, and it helps boost the immune systems of mothers-to-be. It may also help protect against a host of pregnancy-related problems, including preeclampsia (a condition that can lead to organ failure or seizures in a pregnant woman — and could keep the placenta from getting enough blood). Our bodies produce vitamin D naturally when exposed to sunlight, but vitamin D deficiency is overwhelmingly common in the US.
According to a 2009 study published in Scientific American, at least three-fourths of American teens and adults have a vitamin D deficiency. One study suggests these women take a whopping 1,000-2,000 I.U. of vitamin D a day, but most prenatals don’t have those high levels. We looked for supplements that had at least 400 I.U. of vitamin D (the amount recommended by the CDC for infants), and encourage you to speak with your doctor about adding even more through another supplement if necessary. Vitamin A is found in two forms: retinoids and carotenoids. It’s tough to get too much of carotenoids (beta-carotene), the type of vitamin A that’s found abundantly in fruits and vegetables. You would have to eat the equivalent of two pounds of carrots in 24 hours to even notice any adverse effects. But too much vitamin A from retinoids (found in meat, dairy, and eggs) can put a fetus at risk for birth defects. It’s unlikely that small doses of retinoids in prenatal vitamins would prove dangerous for a pregnant woman or her child — Levine notes that vitamin manufacturers “use the lowest necessary dosages” — but we’re eliminating them just to be safe.
Vitamin A deficiencies are rare, since the food we eat is jam-packed full of this important nutrient, so this is one area where you can afford to be choosy. Bellybar Prenatal Chewable Vitamins If you have a hard time keeping down pills, try this chewable. It passed every round of our testing, except for having added sweeteners (1 gram per serving), and is only 40 cents per serving. Look at most vitamin labels and you’ll probably see line after line of words you can’t pronounce. Consider “butylated hydroxytoluene,” for example (it’s a lab-made preservative). Some of these ingredients are used as fillers or binders in pills — and while they probably won’t hurt you, they aren’t necessarily good for you either, and there are great options that don’t include any. We eliminated anything that contained artificial coloring or ingredients that are potentially toxic, including titanium dioxide, carmine, butylated hydroxytoluene, benzoic acid, PEG 3350, talc, and magnesium silicate.
We also cut vitamins containing sweeteners because, in most cases, if you’re older than 10, a vitamin doesn’t need to be sweet. But after talking to some pregnant women — including one on our own team — we realized this isn’t realistic for every woman. Sometimes swallowing pills (and keeping them down) just isn’t going to happen. For those of you with tender tummies, we recommend Bellybar's Chewable Vitamins. We sought out picks that didn’t require taking more than two pills a day. We also looked for options that didn’t smell bad or require swallowing a massive pill — pregnancy isn’t the time for experimenting with your gag reflex. We also investigated whether each prenatal had undergone testing by independent organizations to verify their ingredients, along with their claimed dosages. (Full disclosure: We got our hands on documentation for only one, our top pick.) In the end, six prenatal vitamins made the cut — and five are featured below. Solaray Once Daily Prenatal met our nutritional criteria, but was just too stinky to recommend, ranking somewhere between rotten eggs and farmyard funk on our smell-O-meter.