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The Modern Fertility guide to fertility vitamins and supplements

The Modern Fertility guide to fertility vitamins and supplements

11 min read

The fertility supplement market in the US is big — like, $400-million-a-year big, and has been steadily on the rise over the past decade. This increase in spending on fertility supplements has been attributed to things like the number of people planning for kids later in life, increases in people getting treated for fertility issues, and rising awareness around reproductive health in general and the role that supplements may play. Much like fertility hormone testing, taking a prenatal supplement is considered one major way to get proactive about your reproductive health.

With so many over-the-counter (OTC) options, we created this comprehensive guide to fertility supplements. We sifted through the science from academic articles, society guidelines such as The American College of Obstetricians and Gynecologists, and reports from consumer groups to summarize some of the dos and don’ts when it comes to vitamins and supplements that claim to boost your chances of a healthy pregnancy and improve your reproductive function more generally.

Main takeaways

  • Unlike drugs and many over the counter (OTC) medications, vitamins and supplements don’t undergo the same level of U.S. Food and Drug Administration (FDA) scrutiny. (Crazy, right?) This means that there can be undetected quality, purity and reporting errors. It’s important to be proactive and do the research on how the product stacks up.
  • Science and doctors back vitamins — like folic acid and vitamin D — that provide the body with nutrients for a healthy pregnancy. These may be covered by insurance, depending on your provider.
  • Folic acid to support a healthy pregnancy should be taken a month before trying to conceive (at a minimum!) to help prevent birth defects in babies — but there’s no harm in starting it earlier.
  • What science and doctors don’t support: Supplements that claim to treat medical conditions like anovulation and infertility. For conditions like these, it’s better to stick to evidence-backed, FDA-approved treatments.

What’s considered a vitamin or supplement?

The words “vitamin” and “supplement” are often used interchangeably, but they’re not quite the same thing. Here’s the low down: Vitamins are naturally occurring nutrients, and while we should aim to get vitamins from the foods we eat, they can also be taken in pill/tablet/liquid/powder form. (Think vitamin A, vitamin C, etc.)

Over-the-counter vitamins have a single vitamin, and multivitamins have — you guessed it — multiple vitamins. Supplements are products that often have a combo of vitamins, minerals, and phytonutrients in them. (So... vitamins can be included in supplements — but not all supplements are vitamins.)

How are vitamins and supplements regulated?

In the United States, the Food and Drug Administration’s (FDA) job is to monitor our food, medications, medical devices, and cosmetics to make sure these products are safe for use and consumption. This monitoring process looks really different across categories — for example, the FDA’s monitoring process for mascara is entirely different than its monitoring process for your prescription birth control.

The FDA’s rules and regulations for vitamins and supplements are the same. According to the FDA, something falls under the category of “vitamin” or “supplement” if it is not marketed for the purpose of treating, curing, diagnosing, or preventing a disease or medical condition.

This is where the Federal Trade Commission (FTC) steps in: The FTC looks at the truth and accuracy of any claims made in dietary supplement advertising and marketing — and the FTC and FDA work together to monitor claims made on websites or in other online marketing. Vitamins and supplements can’t be marketed with claims like “will treat infertility” but could technically be marketed with claims like “may promote general reproductive health.”

Because vitamins and supplements are in a different category than drugs, companies don’t actually have to provide any evidence of effectiveness, purity of product, or even safety, before going to market. This doesn’t mean that these products are dangerous or based on pseudoscience (although some might be — more on that below!), but rather that it’s on us to be critical and careful consumers.

Here, we’ll review two main classes of products marketed toward women planning to conceive: prenatal vitamins and supplements, and infertility supplements.

Prenatal vitamins and supplements

Prenatal vitamins and supplements get two thumbs up from the medical community. Even for those of us eating the healthiest of meals, our food likely falls short of several crucial vitamins that are important for developing follicles and embryos.

Your typical prenatal supplement contains good stuff like folic acid, vitamin D, calcium, and iron, and it can be beneficial to take one even if you aren’t actively trying to conceive (TTC). It’s also possible (though not certain) that if you take a women’s daily supplement not specifically formulated for prenatal health, adequate amounts of this good stuff are already included.

When should you start prenatals?

You should begin taking prenatal supplements before actively trying to have kids (or undergoing egg retrieval and IVF procedures) because it may take time for the vitamins and minerals to get to optimal levels in the body. ACOG's official rec is to begin a daily prenatal vitamin with at least 400 micrograms of folic acid starting at least 1 month before pregnancy. A new study has shown, though, that taking a prenatal daily up to a year before conception has been shown to reduce preterm births and prevent neural tube (brain and spine) defects in babies.

Taking a prenatal daily up to a year before conception has been shown to reduce preterm births and prevent neural tube (brain and spine) defects in babies.

Though there’s variability between brands, most prenatals have the same all-star lineup of active ingredients. Let’s briefly get acquainted with each.

Ingredient 1: Folic acid

Prenatal folic acid supplementation is a big deal — such a big deal that it’s been praised as one of the greatest public health breakthroughs of the 20th century. A 1991 study of folic acid supplementation among women trying to conceive was actually stopped midway through when they found that supplementation could prevent 70-80% of neural tube defects in babies (the neural tube is the structure that eventually becomes the brain and spinal cord). It was deemed so effective that it would have been unethical to not give folic acid to all women in the study.
(Added bonus: There are some small studies suggesting folic acid might be beneficial for things like ovulation and egg quality, though much more work needs to be done before we can be confident about these effects.)

The recommended minimum amount of folic acid you should look for is 0.4 milligrams, or 400 micrograms (mcg). There are some reasons why you might need more than the typically recommended amount (if you’re a strict vegetarian or vegan, if you have a history of seizure disorder if you are a heavy drinker, or due to genetics). If you have questions about whether the recommended amount is right for you, make sure to bring up your concerns with your doctor.

Folic acid, folate, or methylfolate?

You may be hearing some buzz about using folate — or methylfolate — over folic acid in prenatal supplements.

First, let’s break down the definitions:

  • Folate is the natural form of vitamin B9 (found in foods like leafy greens, whole grains, beans, eggs, and more).
  • Folic acid is the synthetic form of folate, commonly found in processed foods and prenatal vitamins and supplements.
  • Your body converts both folate and folic acid into its biologically active form, methylfolate.

Genetics plays a role here: The gene MTHFR encodes an enzyme that helps your body metabolize (process) folate and folic acid into methylfolate. Genetic variants in the MTHFR gene can reduce your body’s natural ability to process folate. However, there’s no clear evidence that people with these genetic variants should avoid folate and folic acid, and current guidelines for pregnancy still recommend 400 mcg of folic acid regardless of genetic status.

We stick with the American College of Obstetricians and Gynecologists’ official guidance on nutrition during pregnancy, which recommends that “all pregnant women and all women who may become pregnant should take a daily vitamin supplement that contains folic acid.”

If you have questions about whether you need to look for methylfolate in your prenatal supplement, your doctor can give you a specific recommendation — and if you want to dive really deep into this topic, check out “MTHFR: Addressing genetic counseling dilemmas using evidence‐based literature.”

Ingredients 2 and 3: Calcium and vitamin D

Calcium and vitamin D work together to promote the development of bones and teeth, and further work together in a second way: Vitamin D actually helps with calcium absorption. Because developing babies get their calcium and vitamin D from moms while pregnant, it’s important for both the mom’s health and for the baby’s health to have adequate levels of these compounds.

What are adequate levels? Make sure that your prenatal vitamin contains at least 1,000 milligrams (mg) of calcium, and 600 international units (IU) of vitamin D.

Ingredient 4: Iron

Iron is the building block for hemoglobin, which is a protein in blood cells that shuttles oxygen to organs and tissues throughout the body. The amount of blood you have increases by 30% to 50% during pregnancy; translated into raw numbers, if you had about 4,500 milliliters of blood while not pregnant, you’d have between 5,850 and 6,750 milliliters (ml) when pregnant. Extra iron is required to support this extra blood volume, and iron deficiency (also called anemia) during pregnancy may be associated with babies born too small, or too early. Look for a supplement that contains 27 mg of iron or more. Eating iron-rich foods in pregnancy is also a great idea if you’ve been given a diagnosis of anemia.

Comparing prescription and over-the-counter prenatal vitamins

No matter how you get your prenatal vitamins, chances are they’ll have the same main ingredients. The main differences between prescription versus over-the-counter (OTC) prenatals come down to small differences in dosages and how you pay for them.

Prescription prenatals often contain closer to the upper end of the recommended amount of a vitamin or mineral (for example, prescription prenatals will contain closer to 1,000 mcg of folic acid, compared to the 400 mcg found in OTC formulations).

Depending on your insurance plan, prescription prenatal vitamin and supplements may be covered. You can also use your FSA and HSA dollars (refresher on what those are here) toward OTC prenatal vitamins (fun fact: you can also use those dollars for your MF test!).

Prenatals: Takeaways

  • Prenatal vitamins with sufficient amounts of folic acid, calcium, vitamin D, and iron are effective and safe, with heaps of studies to back up their beneficial effects.
  • Taking a prenatal supplement daily before conception (and then throughout the first trimester) is key: Doing this daily up to a year before conception has been shown to reduce preterm births and prevent neural tube (brain and spine) defects in babies
  • There’s no demonstrated harm in starting to take these supplements even if you are not currently TTC.
  • Some women’s supplements that are not meant for prenatal health specifically may even already have sufficient amounts of these compounds, meaning there may be no need to switch to something that has the ‘prenatal’ label specifically.

It’s always smart to talk to your doctor (especially if you have any diagnosed medical conditions) before making any decisions or starting a supplement regimen to figure out what’s best for you.

Infertility supplements

Here’s where things get a little less… scientific and thus, recommendations aren’t so clear. The supplements that we talked about above are supplements that help support a healthy pregnancy, but they don’t make any claims about helping you get pregnant in the first place. There are, however, a whole host of supplements that do make such claims — claims like “promotes natural fertility,” “improves ovulatory performance,” and “improves your pregnancy chances.” Now, don’t get us wrong: It would be exceedingly great if there was scientific evidence to support supplements doing those sorts of things. Unfortunately, as of today, that evidence just doesn’t exist.

(Small caveat here: if you are severely malnourished and depleted, some of these supplements might help get you back to baseline. But, this would be the case for a small minority of women.)

In a recent market scan, scientists at the Center for Science in the Public Interest dug for evidence of effectiveness for 39 different women’s fertility supplements (you can see the full list here). They scoured company websites and contacted company service reps directly to get their hands on data showing these supplements did anything they claimed — made women ovulate more regularly, shortened TTC, prevented miscarriages, or otherwise helped cure infertility.

To their credit, a (very, very small) minority of companies did actually reference scientific studies. But overwhelmingly to their discredit, not a single referenced study found positive effects on ovulation, time to pregnancy, or pregnancy outcomes in women. In fact, most didn’t even look at these outcomes. One company referenced one published study (yay) that was conducted 78 years ago (yikes)… in men (double yikes).

The majority of companies pointed the investigating scientists to their customer reviews as evidence for their product being effective. While people’s experiences and opinions are certainly valuable (I for one spend entirely too long reading customer reviews before buying anything!), they are simply not a stand-in for science. They are not a stand-in for all the stuff us researchers nerd out over: large-scale, well-controlled, double-blind studies assessing different clinical endpoints like ovulation frequency and regularity, time-to-pregnancy, or pregnancy outcomes.

The danger in these so-called infertility supplements doesn’t lie in their ineffective chemical composition, but rather in the false sense of hope they may engender for those trying to conceive. Many of these supplements position themselves as “perfect natural alternatives to fertility drugs.” While FDA-approved fertility drugs might not be “natural,” we know they work and we know how they work — if we didn’t know these two key things, the drugs wouldn’t have gotten the FDA stamp of approval. Further, by suggesting women use infertility supplements rather than science-backed treatments, women are spending time and money on these supplements, both of which are precious and finite resources when it comes to reproductive health.

Infertility supplements: Takeaways

Supplements that claim to do things like cure infertility aren’t up to snuff when it comes to being backed by good research. If you or your partner think you may have a condition that could interfere with fertility, talk to a doctor who can help you get to the bottom of things and direct you toward treatments and interventions that do get the science thumbs-up.

Your best advocate in the fertility supplement world = you

Because of the FDA’s relatively hands-off stance toward supplements and vitamins, companies are allowed to make pretty bold claims about their products, and these claims are often not backed by research. Here are tips and tools you can use to be your own savvy advocate when evaluating different supplement options.

  • Look up how supplements rank when tested by independent companies. Groups like Labdoor and ConsumerLab evaluate the content of different prenatal vitamins and supplements to see whether bottles contain the amounts and types of compounds that they advertise. (This isn’t just us being paranoid — some supplements do not even contain the main compounds advertised in them.) Other independent organizations like NSF and USP also evaluate both product contents and manufacturing practices to ensure they meet quality standards. You can look for their certification seals on product labels.
  • If possible, get your blood levels of certain compounds like folate, vitamin D, and iron checked — this will help guide you on whether and how much you should be adding via supplements.
  • Talk to your doctor at least three months before you’re TTC (whether naturally or before starting egg freezing or IVF-related procedures) to discuss what the best supplementation regimen may look like for you, given your medical and reproductive health past and present. You’ll also want to mention all the medications, vitamins, and supplements you are currently taking, as some might have a negative effect on fertility.

Taking a prenatal supplement is one major way to get proactive about your fertility. If you’re looking for more ways to plan ahead, you can consider things like fertility hormone testing to check in with your hormones. Our goal is to give you everything you need to be proactive about your reproductive health and start important conversations with your partner, your friends, and your doctor.  

This article was medically reviewed by Dr. Nataki Douglas, the Chair of the Modern Fertility Medical Advisory Board, as well as Dr. Jane van Dis, co-founder and CEO of Equity Quotient, and Medical Director for Ob Hospitalist Group.

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Talia Shirazi

Talia is a biological anthropology PhD candidate at Penn State, passionate about women's reproductive health and behavioral neuroendocrinology.

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