14 best prenatal vitamins for soon-to-be moms, according to experts

And that, kids, is exactly why prenatal vitamins were invented.

What exactly are prenatal vitamins?

Prenatal vitamins are there to fill in any nutritional gaps and make sure there is an abundance of all the vital nutrients your baby needs to grow-especially magnesium, zinc, calcium, vitamins B and C, and folate, says G. Thomas Ruiz , MD, ob-gyn at MemorialCare Orange Coast Medical Center in Fountain Valley, California.

Supplemental folate, in particular, is very important as it's been shown to reduce neural tube defects in babies, and you need at least 400 micrograms a day, according to the World Health Organization (WHO).

Most of these vitamins are water soluble, meaning you'll just pee out any excess, Dr. Ruiz says. (So, you don't need to worry about OD'ing.) There is one exception to this rule, however: iron, which can be toxic in large doses.

Pregnant women need 30 to 60 milligrams of iron each day, according to the guidelines from the WHO . Most prenatal vitamins come fortified with extra iron, so as long as you're sticking to what's in your daily prenatal (and not supplementing with even more iron), you'll be fine, Dr. Ruiz says. (Caveat: If you're anemic, you might need more, so Dr. Ruiz recommends discussing your individual needs with your doctor.)

Okay, so when do I need to start taking prenatal vitamins-and for how long?

Ideally you should start taking them as soon as you start trying to conceive, Dr. Ruiz says. (FYI: It's a myth that they will increase your fertility, though.) Your baby will need those extra nutrients from the moment of conception, Dr. Ruiz explains.

Continue to take the vitamins throughout your pregnancy and afterwards, for as long as you're breastfeeding, he advises.

What do I really need in a prenatal vitamin?

Sifting through drugstore shelves or Amazon suggestions is super intimidating. And don't worry, it's not just you-all of those options don't just start to sound alike, they really are very similar, says Wendy Goodall McDonald , MD, a Chicago-based ob-gyn.

The key, however, is making sure you start taking a vitamin with at least 400 micrograms of folic acid as early as possible (yes, even before conception if possible). You should also look for options that will help you meet the daily recommended amounts of 600 international units of vitamin D, 1,000 mg of calcium, and at least 27 mg of iron, according to the American College of Obstetricians and Gynecologists (ACOG).

As for the other ingredients listed? There's no hard and fast rule as to how much, say, biotin you should take on the reg, as "biotin and many of the other minerals quantities aren't backed by scientific evidence when it comes to the absolute required quantities in a prenatal," Dr. McDonald explains.

So the question still remains: which prenatal vitamin is the right prenatal vitamin? While it's different for everyone (for example, some people might have tummy troubles for one versus another), here are the top doctor-approved prenatal vitamins on the market, including the best-selling ones on Amazon to add to your cart, STAT. And to top it all off? Insight from the pros as to why you should add 'em to your cart.

1. One A Day Women's Prenatal Multivitamins

This is the most popular brand of prenatal vitamins on the market, and it's a solid choice, says Hillary Wright, MEd, RD, director of nutrition counseling at Boston IVF and an expert in prenatal nutrition.

It's not necessarily fancy, but it gets the job done for a reasonable price and, best of all, it's been verified by an independent lab so it actually contains what it says it contains, she adds. (Which isn't always the case with supplements as they're not monitored by the FDA.)

2. Nature Made Prenatal + DHA 200 mg Multivitamin

The best thing about this prenatal vitamin: a large dose of DHA, a fatty acid crucial to fetal brain development, Wright says.

"A lot of prenatals advertise they have this but they have a minuscule amount-you want a minimum of 200 mg of DHA per serving," she says. You can also get DHA by taking a separate fish oil supplement .

3. Vitafusion Prenatal Gummy Vitamins

This is the most popular chewable prenatal on the market for good reason: It has quality ingredients and it tastes good, Wright explains.

There is one downside to all gummy vitamins , however: The gummy ingredients (you know, like sugar) displace some of the vitamins. So if you want to make sure you're getting the most nutrition for your money, stick to the pills, she says.

4. Rainbow Light Prenatal One Multivitamin

This super-popular prenatal vitamin is also one of the priciest-but it might be worth it, per Wright. The brand is known for its high quality and it includes prebiotics and probiotics to help keep your gut bacteria (and therefore, you) happy.

These extras aren't necessary and are best gotten through food, according to Wright. But-and this is a big but-they may be a good addition for some pregnant women, especially if you're struggling to get enough fiber, she adds.

5. Mama Bird Prenatal Multivitamin

These vitamins contain "methylated folate"-a pretty buzzy word in the prenatal vitamin world. Folate is one of the most important vitamins in prenatal pills, but some women have a genetic condition that makes it hard for their bodies to convert the folic acid in most prenatals to the active form the body can use, Wright explains.

But there's a catch: You won't know if you have the condition unless you have genetic testing done. So if you want to be super-safe and cover all your bases, then a methylated version of folate might be worth the money. Still, she emphasizes that for the majority of women, the regular (and more affordable) variety is just fine.

6. TheraNatal Complete Prenatal Vitamin & Mineral Supplement

This prenatal is Wright's personal favorite and the one she recommends to her clients. It contains iodine and choline-two minerals vital to hormone regulation, fetal growth, and brain development-that are often missing from other prenatal vitamins.

Ideally, you want 150 micrograms of iodine and 450 milligrams of choline (which also is, btw, a key nutrient in eggs ) every day, according to Wright, who also notes that this product in particular is also independently tested and has a high standard of quality.

There is one major downside: They don't come cheap. These are by far the most expensive OTC option on the list, although you may be able to get them cheaper through your doctor or buying them directly from their site .

7. Ritual Prenatal Vitamins

These vitamins are great because of what they don't have: calcium. "Calcium and iron compete with each other for absorption," says Alyssa Dweck , MD, an ob-gyn in Westchester County, New York, and co-author of V Is for Vagina. "I recommend getting iron from a vitamin and calcium from your diet," she says, since it's much easier to get calcium from foods (think: dairy, greens) than iron.

These vitamins minty favor is a nice bonus for women experiencing morning sickness , as mint is known to control nausea, Dr. Dweck explains.

8. Pure Encapsulations Prenatal Nutrients

This vitamin is a good option because it contains the methylated types of folate and B12. Again, many pregnant women carry a genetic mutation that doesn't allow the body to convert folate and B12 into forms usable in the body, says Felice Gersh , MD, a board-certified ob-gyn and director of Integrative Medical Group of Irvine in Irvine, California.

If the body cant properly convert these to the usable vitamin forms then its as though none is taken, or worse, she says.

9. Thorne Basic Prenatal

This one's another great choice according to Dr. Gersh, as it also contains the methylated forms of folate and B12. Plus it also has more even more folate (a full milligram more, in fact) than most vitamins out there, which makes it ideal for women who dont get enough green leafy vegetables into their diet.

Another plus? "This vitamin is also high in vitamin D and provides a healthy blend of calcium citrate and malate, though it does take three capsules daily though to get these amounts, she says, which differs from the usual one-pill regiment for most prenatal vitamins.

10. Garden of Life Vitamin Code Raw Prenatal

In addition to being a good source of vitamin D, it also offers a blend of vitamin A , which is known for being beneficial for your (and your fetus) eyes per WHO , and contains ginger to soothe nausea , probiotics that support your immune system, and an organic vegetable blend.

This is a great option for women looking for a very affordable option without any unhealthy binders and fillers, Dr. Gersh adds.

11. Vitapearl

Unlike the others on the list thus far, this small, easy-to-tolerate (read: less risk of GI distress) pill is only available through an Rx from your doc. So now you're probably wondering: is a prescription prenatal better than an OTC? Not necessarily, according to Dr. McDonald, who says she doesn't having a preference for one over the other.

What draws people to an Rx option rather than the more "trendy" OTC products is that your health insurance might cover the cost if the specific prenatal is fits your plan, Dr. Dweck explains. If that sounds like something you'd be interested in, consult your insurance plan to see what, if any prenatal vitamins, are covered and then chat about it further with your doc.

12. OB Complete One (+ Petite)

This prescription option recommended by Dr. McDonald stands outs for being loaded with iron-40 mg to be exact-which is particularly great because, per ACOG , during pregnancy your body needs extra iron to help make more blood to carry all that oxygen to the fetus. Just be sure to avoid eating or drinking dairy within 30 minutes of taking this vitamin, as the calcium can interfere with iron absorption, she explains.

13. Prenate Mini

If even the word "vitamin" freaks out out (hi, huge horse pills), Dr. McDonald recommends Prenate Mini, the micro vitamin that still provides you with the essential nutrients needed for a healthy pregnancy. Of particular note is its large amount of DHA-350 mg-which should free you from potentially having to take an added DHA supplement.

Quick reminder: DHA is a type of omega-3 fatty acid (you know, the brain-boosting fat that you can frequently find in fish). Omega-3 fatty acids are believed to play in an important role in the fetus' brain development before and after birth, according to ACOG , which is why extra DHA is super important.

14. Flintstones Complete Chewables Childrens Multivitamins

Yep, you read that correctly. Unfortunately, iron, especially in larger doses, can cause GI distress, according to Dr. Dweck. If you're finding that you really can't tolerate iron-rich vitamins (or really any prenatal vitamins), and/or are overwhelmingly nauseous, Dr. Dweck suggests Flintstones Complete Chewables as a last resort. They're iron-free and "better than nothing," says Dr. Dweck.