How Prenatal Vitamins Increase Your Chances of Pregnancy

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Philip Druce

By Philip Druce

Prenatal vitamins are multivitamins that are specifically designed to support women's nutrition when trying to conceive, and once pregnant.

Women trying to conceive and pregnant women need additional nutrients, especially extra Folic Acid and Iron. Today you will learn why prenatal vitamins are so important, when you need to start taking them and how they impact your fertility.

Why take prenatal vitamins?

  1. Prenatal vitamins increase your chances of conception.
  2. They prepare your body for conception and pregnancy.
  3. Folic acid helps prevent abnormalities and maintain good overall health of your baby.
  4. Iron supports sufficient growth and development of your baby.
  5. They replenish your nutrient stores.
  6. Health experts around the world recommend you take them.

I'm sure you agree, these are very good reasons to be taking prenatal vitamins.

When should you start taking prenatal supplements and why?

It's recommended that you start at least three months before conception.


  1. Helps ensure your body has all the required nutrients available prior to conception.
    • It takes over a year for an egg to develop, with most of the maturing occurring in the three months prior to ovulation, so it's important that you get all the required nutrients during this development stage.
    • Your baby needs these nutrients to be available at the point of conception, not afterwards.
  2. Improve fertility - Prenatal vitamins can actually improve fertility.

More on these points below.

Unfortunately, many women trying to conceive are not aware of the importance of starting BEFORE seeing a positive pregnancy test. Ovulation Calculator asked 81,156 women who were actively trying to conceive if they were taking a prenatal vitamin, the result was alarming. 68% said "No".

Are you taking prental vitmains?

We then asked the same women how long had they been trying to conceive. As you can see in the graph below, the results ranged from 74% for women "Just Starting", to 62% for women that had been trying for "12 months or more".

These numbers may seem unbelievable, but it just goes to show we are not well informed when it comes to the importance of nutrition before conception.

Women trying to conceive but not taking a prental vitamin

To see a breakdown of this by country, take a look at the following chart which represents women taking prenatal vitamins whilst trying to conceive in the USA, UK, Canada and Australia. The results show that women in the USA are less likely (31%) to be taking one before getting pregnant. Women in Canada are most likely (52%).

Women taking a prenatal vitamin by country

What you should look for in a prenatal vitamin

Now that we know the importance of beginning prenatal vitamins as early as possible, let's take a look at what you should be looking for in a prenatal vitamin and why.

NOTE: Each of the vitamins and minerals below have an RDI (recommended daily intake1) value. RDIs are provided for vitamins and minerals for pregnant and lactating women and can be found on the 'Supplement Facts' label on the bottle. The value is what your body should be getting from all sources (balanced-diet and supplements combined), it is not necessarily the value that should be in a prenatal vitamin alone. For example, the RDI for vitamin A is 8000 IU, and you may get half of this from your diet and half from a supplement.

#1 Folic Acid

Folic Acid

Folic acid (folate) is extremely important. It's critical that your body has enough of this vitamin before and during pregnancy.

What is folic acid?
Folic acid is a type of B vitamin (B9) found in supplements and fortified foods (foods that have vitamins added). It is a synthetic (man-made) form of folate. Whilst folate can be obtained from foods, the body can actually absorb the synthetic version easier. The term folate is often used for both folic acid, and folate found in foods.

How does it help? Folic acid plays a role in the development of your baby's spine, brain and skull, especially during the first four weeks of pregnancy.

Taking a prenatal vitamin with enough folic acid will reduce your baby's risk of developing a neural tube defect (NTD).

NTD occurs when the neural tube fails to close properly. Failure of the closure of the neural tube can lead to abnormalities of the spine, brain, or skull and result in stillbirth or a lifelong disability.

NTD Neural tube location

The most common NTD is spina bifida. For this reason, it is recommended that any woman who can get pregnant should take at least a folic acid supplement, even if they are not planning on becoming pregnant.

Women who have already had an NTD-affected pregnancy may require higher amounts of folic acid and need to speak to their doctor about how much intake they require.2

Having adequate levels of folic acid can also reduce the risk of miscarriage according to a study in Sweden. In the study, women that had inadequate levels of folic acid were 50% more likely to have a miscarriage.3

RDI: At least 400 mcg (micrograms) whilst trying to get pregnant, and 800 mcg once pregnant.4

Best folate food sources: Lentils, liver, dried beans, asparagus, green leafy vegetables, folate-fortified breakfast cereals and avocados.

Folate vs Folic Acid

Folate is a naturally-occurring vitamin found in foods.

Folic acid is a synthetic dietary supplement found in supplements and added to fortified foods.

Folate cannot be produced by your body, it must be obtained from either diet or supplementation. You probably consume folate on a regular basis through your diet, but you would have only had folic acid through supplements or fortified foods.

The vitamin not only helps prevent NTD, it also helps prevent anemia, some forms of cancer, cardiovascular diseases and poor cognitive performance in babies.5

Another important difference is folic acid (the synthetic form) can actually be absorbed easier by the human body. The bioavailability of folic acid is about 85% whereas folate in food is about 50-60%.6

On a population level, nutritional requirements for folate cannot be obtained from a "varied diet" as recommended by national health authorities.

Because of the importance of the vitamin in our diet, the difference in bioavailability and low consumption of folate-rich foods, many countries have made it mandatory to add folic acid to grain products.7 However, it is still recommended that women trying to conceive, and pregnant women, take extra.

#2 Iron


During pregnancy, you have a 50% increased need for iron. Iron is important to maintain healthy blood and reduce your risk of developing anemia (a lack of healthy red blood cells) during pregnancy.

It is also important to obtain enough iron to help your baby grow properly and build up a good supply of iron for after birth.

Studies show that babies that do not get adequate iron before birth are more susceptible to illnesses and learning difficulties.

Iron may also help prevent anovulation (when ovulation does not occur). A study found that women who consumed iron in a supplement had a significantly lower risk (60%) of ovulatory infertility compared with women who did not take iron in a supplement.8

You may find the iron is hard to digest. If this is the case, try taking the prenatal vitamins with a meal or before bed to ease its effect on your stomach.

RDI: 18 mg (milligrams) before pregnancy, 27 mg whilst pregnant and 9 mg whist lactating.9

Best iron food sources: Lean red meat, poultry, green leafy vegetables, fish, beans, whole grains, tofu and iron-fortified foods such as breakfast cereals, breads and pastas.

#3 Calcium


Prenatal vitamins should also contain calcium. Calcium is important during pregnancy, especially during the third trimester. This is because your baby's bones are growing rapidly during this time.

Women with inadequate levels of calcium during pregnancy may be at risk of increased bone loss. This is due to the baby drawing what it needs from the mother's bones.

Most prenatal vitamins will include about 200 mg of calcium. They only include a small amount because the calcium molecule is large. However, WebMD says four servings of dairy products such as milk, cheese and yogurt per day will help provide you with enough calcium.

RDI: 1,300 mg for pregnant and lactating women.

Best calcium food sources: Dairy products, green leafy vegetables and fish.

#4 Vitamin B12

Vitamin B12

An increased intake of folic acid might mask a vitamin B12 deficiency; so ensure that your prenatal vitamin contains vitamin B12 so that you are not at risk for deficiency.

Vitamin B12 is needed to form DNA, make healthy blood cells, and keep your nerves working properly. Low intake of vitamin B12 can lead to pernicious anemia.

Vitamin B12 may also reduce the risk of miscarriage by helping the uterus lining (endometrium) prepare for implantation.10

RDI: 8 mcg for pregnant and lactating women.

Best vitamin B12 food sources: Found in animal products like red meat, poultry, egg, dairy and fish. And vitamin B12 fortified foods such as cereals and soy milk.

#5 Vitamin D

Vitamin D

Vitamin D is needed for the body to absorb and use calcium, important in ensuring you and your baby have healthy bones.

According to several studies vitamin D may also help with fertility. One study found that women with higher vitamin D levels were significantly more likely to achieve pregnancy from in vitro fertilization (IVF) compared with women with less vitamin D levels.11

In another study, women with higher vitamin D levels had a four times better chance of a successful IVF procedure compared with women with low levels of vitamin D.12

Vitamin D also stimulates anti-Müllerian hormone (AMH) production, which supports ovarian reserve (remaining eggs in your ovaries) preservation.13

You can get vitamin D from exposure to the sun, but some climates are not ideal for this, and vitamin D is not abundant in our food sources. Milk and many cereals are fortified with vitamin D, so be sure to include these in your diet.

RDI: 400 IU (international units) of vitamin D per day.

Best vitamin D food sources: Fatty fish such as salmon, cheese, egg yolks, and vitamin D fortified foods such as milk, soy beverages, cereals, and orange juice. You can also get vitamin D when your skin is exposed to UV from the sun. The length of exposure required varies depending on time of year, time of day and location.

Learn more about other vitamins and minerals you can expect to find in your prenatal vitamin.
Tap on View all or a specific Vitamin / Mineral below.

Supplement Facts

When looking to see what is in a prenatal vitamin, have a look at the supplement facts label on the box or bottle. Here's an example of a supplement facts label and how to read one.

Prental Vitamins Supplement Facts Label Explained

The table below shows the Food & Drug Administration's RDIs for pregnant women.14

Vitamin or Mineral Pregnant and Lactating Women Units of Measure
Vitamin A 8,000 IU
Vitamin C 60 mg
Calcium 1,300 mg
Iron 18 mg
Vitamin D 400 IU
Vitamin E 30 IU
Thiamin 1.7 mg
Riboflavin 2 mg
Niacin 20 mg
Vitamin B6 2.5 mg
Folate 800 mcg
Vitamin B12 8 mcg
Biotin 300 mcg
Pantothenic acid 10 mg
Phosphorus 1,300 mg
Iodine 150 mcg
Magnesium 450 mg
Zinc 15 mg
Copper 2 mg
Section Summary

Choose a prenatal vitamin that includes the following:

  • Folic Acid to help reduce neural tube defects and miscarriage
  • Iron to support your baby's growth and development
  • Calcium to help build your baby's bones and prevent your bone loss
  • Vitamin B12 to form DNA, build healthy blood cells, and develop a healthy nervous system
  • Vitamin D for healthy bones, by helping your body absorb and use calcium

The infographic below will help you remember which nutrients your body requires, feel free to print it out.:

What's in a prenatal vitamin?

Embed the "What's in a Prenatal Vitamin" infographic on your site (copy the code below):

<div style="clear:both"><a href=""><img src="https://www.ovulationcalculator.com" title="What is in a Prenatal Vitamin" alt="What is in a Prenatal Vitamin" border="0" /></a></div><div>Courtesy of: <a href="">Ovulation Calculator</a></div>

How do prenatal vitamins increase your chances of conception?

Prenatal vitamins have actually been shown to improve fertility according to a 2011 study.15

In the study, women undergoing ovulation induction were allocated to either receive multiple micronutrients (including folic acid) or only folic acid. The study found that the women taking a combination of micronutrients had a significantly higher pregnancy rate (66.7%), compared with those using only folic acid supplementation (39.3%). Promoting efficient energy metabolism, antioxidant release and healthy organs is the proposed mechanism for this improvement.

Folic acid is also an essential nutrient that is required to form red blood cells and produce DNA, the building block of your eggs and the human body.16

Our data shows that you are 30% more likely to conceive when taking a prenatal vitamin.

As mentioned, in a recent survey we conducted, only 32% of women trying to conceive were taking a prenatal vitamin. Of nearly ten thousand recorded pregnancies, 30% more women were taking a prenatal vitamin than not.

Are there different prenatals I should be taking before conceiving vs. when I am pregnant?

Certain vitamins and minerals are more important at different times. But generally, you can take the same prenatal supplement before and after conceiving, and simply adjust your diet while pregnant to include higher amounts of calories, vitamins and minerals. However, if you find it hard to keep on top of what foods to eat, there are prenatal vitamins out there that are made for each stage of pregnancy and lactating women.

Pregnant women need extra calories per day.17

Trimester Calorie Intake

Recommended dietary intakes (RDIs) for 14 of the 21 essential micronutrients increase during pregnancy.18

Important vitamins and minerals before conceiving:

Important vitamins and minerals after conceiving:

Which prenatal supplement is right for me?

To choose the best supplement for you, consult with your doctor first. They will need to assess your current nutrition levels and identify any deficiencies present. They will need to take into account your dietary restrictions, if any. For example, vegetarians may struggle more with iron and vitamin B12 levels. Based on all of these factors, you and your doctor can choose the best supplement for you.

Size and forms

Some people struggle with swallowing tablets, so there are a variety of types of prenatals. They come in liquid and chewable forms too, so if you struggle with swallowing tablets, you can still get your micronutrients in.

Prenatal Vitamin Tablets Types

Micronutrient levels

Prescription prenatals generally have higher amounts of folate (around 1000 mcg of folic acid), which is the upper limit of the recommended daily intake. Over the counter (OTC) prenatals generally have only around 600 mcg of folate and no more than 800 mcg. The same story goes for iron, with prescription prenatals generally having higher iron levels.


Due to their higher micronutrient level, prescription prenatals are more expensive than OTC prenatals. Take into account your finances in combination with the need for that extra bit of folate or iron. Discuss your diet and your micronutrient levels with your doctor before choosing the best option for you.

Vegetarian, vegan friendly prenatal vitamins

If you are looking for a vegetarian or vegan option, or something that is organic, read on to learn the differences and your options.

What are the differences between organic, natural and regular prenatal supplements?

Prenatal Vitamin Types

This choice is something you should discuss with your doctor.

Are there prenatal supplements for vegetarians or vegans?

Vegans and vegetarians often have gaps in their diet, due to a lack of meat or animal products. An example of this is vitamin B12 which is mainly found in animal products (red meats, fish, cheese, milk etc.) and iron is rich in meats. For this reason, they may benefit more from a broad prenatal plus individual vitamin tablets, such as iron tablets. Some prenatal supplements cater to vegans and vegetarians, with vegan sourced ingredients and tailored micronutrients.

What is DHA and when should I choose a prenatal containing DHA?

DHA stands for the omega-3 fatty acid, docosahexaenoic acid, and it is not found in every prenatal. It is important for developing healthy nerves and eyes in your baby. The major source of DHA is fish.

Vegetarians may find it difficult to consume enough fish and enough DHA, and many individuals worry about the levels of mercury consumed with fish. In these instances, a prenatal containing DHA may be beneficial. If you are unsure about your need for this fatty acid, consult your doctor to discuss your concerns.

Rapid development of the nerves and eyes occurs in the second half of pregnancy (mainly in the third trimester). Based on this, supplementation of omega-3 fatty acids, especially DHA, is thought to be more important later in pregnancy.20

Prenatal vitamins vs a regular multivitamin

Prenatals are tailored to the right quality and quantity for pregnant women and women trying to conceive. Certain vitamins (A, D, E and K) are fat soluble and are stored for long periods of time. These stores can therefore be 'overloaded' with normal multivitamins, and vitamin A for example, can actually be toxic to the baby at high levels. Prenatal supplements also contain specific ingredients to assist with the healthy development of a baby, for example Folic Acid.

Below is an example of some of the differences in nutrients you may find in a women's multivitamin compared with a prenatal vitamin:

Vitamin or Mineral Women's Multivitamin Prenatal Vitamin % Difference in Prenatal Vitamin
Vitamin A 5,070 IU 4,000 IU 21% less
Vitamin C 75 mg 90 mg 20% more
Vitamin D 1,000 IU 400 IU 60% less
Vitamin K 50 mcg 30 mcg 40% less
Thiamin 1.1 mg 1.4 mg 27% more
Riboflavin 1.1 mg 1.4 mg 27% more
Niacin 14 mg 18 mg 29% more
Vitamin B6 2 mg 1.9 mg 5% less
Folic Acid 400 mcg 800 mcg 100% more
Vitamin B12 6 mcg 2.6 mcg 57% less
Calcium 200 mg 250 mg 25% more
Iron 18 mg 27 mg 50% more
Zinc 8 mg 11 mg 38% more

Do vitamins have other benefits?

Taking a prenatal vitamin not only helps you prepare for conception and pregnancy, it also helps you receive more than the minimum amount of vitamins and minerals necessary to prevent deficiency diseases.

Many of us do not get the all the required vitamins and minerals we need from our diet. Even when we eat a healthy balanced diet it is hard to get everything we need to prevent disease, let alone achieve optimal health.

Whilst taking a supplement is not a replacement for eating a healthy balanced diet, supplements can provide you with key nutrients that are hard to get from food.

Mark Hyman, MD a practicing physician and a pioneer in functional medicine said 92% of the population in the U.S. are deficient in one or more vitamins, when asked if we need vitamins or not, he said...

Do We Need Vitamins?

Mark goes on to say "In today's world, everyone needs a basic multivitamin and mineral supplement. The research is overwhelming on this point".

Morning sickness relief - According to the American College of Obstetricians and Gynecologists, taking a supplement with vitamin B6 can also help combat morning sickness symptoms.21

What are the side effects of taking prenatal vitamins?

Side effects from prenatals are generally due to excessive amounts of certain vitamins, or irritation to the gastrointestinal tract.

These side effects are generally mild and you should consult your doctor if these become irritating or if you have any concerns at all.

Remind me, what does my baby need?

What Baby Needs

In summary the research overwhelmingly suggests that you should be taking a prenatal vitamin when trying to conceive, as well as during pregnancy and lactation.

Take a look at this inforgraphic for what you would have to eat in order to get the same amount of nutrients as a prenatal vitamin:

What do you have to eat for the same amount of nutrients as a prenatal vitamin?

Embed the "What Would You Have to Eat" infographic on your site (copy the code below):

<div style="clear:both"><a href=""><img src="https://www.ovulationcalculator.com" title="What do you have to eat for the same amount of nutrients as a prenatal vitamin?" alt="What do you have to eat for the same amount of nutrients as a prenatal vitamin?" border="0" /></a></div><div>Courtesy of: <a href="">Ovulation Calculator</a></div>

To help you understand mineral rich foods as an alternative to prenatal vitamins, take a look at the following infographic:

Prenatal Vitamins & Mineral Rich Foods

Embed the "Mineral Rich Foods" infographic on your site (copy the code below):

<div style="clear:both"><a href=""><img src="https://www.ovulationcalculator.com" title="Prenatal Vitamins & Mineral Rich Foods" alt="Prenatal Vitamins & Mineral Rich Foods" border="0" /></a></div><div>Courtesy of: <a href="">Ovulation Calculator</a></div>

15: Prospective randomized trial of multiple micronutrients in subfertile women undergoing ovulation induction: a pilot study, Agrawal, Rina et al, Reproductive BioMedicine Online, Volume 24, Issue 1, 54-60
What did you learn about prenatal vitamins? Or have a question? Leave us a comment below.

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  1. Erica Mar 25, 2018
    Okay my name is Erica and I take pregnant pills does it help me to have a baby this is my first time taking them please help me????
  2. Omodara Mar 29, 2018
    This is so educative. Thanks so much
  3. Future Aug 12, 2018
    This was sooooo helpful, and now I’m very well educated! Thank you
  4. Sophy Sep 11, 2018
    Thanks i will try the vitamins
  5. Chinyere Oct 04, 2018
    How do i get the vitamins and what is the cost

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