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  • Writer's pictureDr. Mallory Murray, NMD

Prenatal Vitamins: What to Look for and What to Avoid

Vitamins and minerals are essential for everyday life. They help with everything from hormone production and regulation to energy maintenance and immune support. During pregnancy your nutrient needs change to support the additional task of growing a baby. Keep reading to find out how to choose the best prenatal vitamin for you and when you should start taking it.

When should you start taking a Prenatal Vitamin?

The American College of Obstetricians and Gynecologists, ACOG, recommend you start taking a prenatal vitamin at least 3 months before trying to get pregnant. This is because if you are deficient in folic acid/folate when you get pregnant it can result in neural tube defects.

Neural tube defects are abnormalities in the fetal brain and spine, the most common being spina bifida and anencephaly. The neural tube forms in the first few weeks of pregnancy, before most women even realize they are pregnant. This is why it’s so important to begin taking a prenatal vitamin before you are pregnant.

If you are taking oral contraceptive pills (OCPs) or have a history of taking OCPs you still want to start taking a prenatal vitamin. OCPs deplete important nutrients including folate. OCPs are also not 100% effective, so it is still important to make sure you have adequate folate stores in case of an unintended pregnancy.

What’s the difference between a Prenatal and a Multivitamin?

Prenatal vitamins are designed to meet the specific needs of your body during pregnancy whereas a multivitamin is just designed to meet your needs in every day life. This means that prenatals are higher in key nutrients including Iron, DHA, calcium, vitamin D, and folate when compared to a standar multivitamin.

Another reason multivitamins aren’t as appropriate for pregnancy is that they tend to have higher levels of Vitamin A. While vitamin A is an essential nutrient in pregnancy, too high of levels can be teratogenic meaning it can cause malformations or birth defects. The levels in an average multivitamin are not close to teratogenic levels, but it is still something to be mindful of.

One a Day Prenatals: Yay or Nay?

High levels of vitamins are necessary to aid in the formation and development of your baby. Taking your vitamins in divided doses helps you to achieve maximum nutrient absorption. One a day vitamins are taken just like the name says, once a day, and the nutrients may not be fully absorbed. One a day vitamins also tend to have lower levels of nutrients, because one capsule can only fit so much inside of it. Keep in mind that if one pill a day is all you can stomach, then it is still better than nothing and you should feel good about getting even one pill in.

Are gummy prenatals good?

There are a few cons that come with gummy vitamins. Like one a days, gummies rarely contain the levels of nutrients that are ideal for pregnancy. It’s just too difficult to load up a gummy with high levels of vitamins and still expect it to taste good. Also, gummies usually contain food coloring and sugar. However, much like a one a day vitamin, if a gummy is all you can stomach, it’s better than nothing.

What nutrients to look for in a Prenatal

*All recommended daily values in this section have been taken from the American College of Obstetricians and Gynecologists

Methylfolate- 600mcg

Folate is the naturally occurring form versus folic acid which is a synthetic form. People that are poor methylators don’t convert folic acid into folate efficiently and can end up deficient. Taking the folate form can allow you to utilize the maximum amount that your body needs.

DHA- 400mcg

DHA is an essential component in the development of your babies eyes, brain, heart, and nervous system. This study was done that looked at DHA supplementation and pregnancy outcomes. The findings showed that 600mg per day of DHA in the last half of pregnancy resulted in preterm births and the group with DHA supplementation had higher birth weights.

I usually recommend an additional Omega-3 supplement to increase the amount of DHA a pregnant women is getting daily.

Methylcobalamin- 2.6mcg

Methylcobalamin is the natural form of B12 that is found in foods. It has a methyl group attached to it which makes it the more readily absorbed form of B12, because it bypasses the need for your body to attach a methyl group for absorption (poor methylators struggle with this step and can become B12 deficient).

B12 helps support the formation of a healthy nervous system and the formation of red blood cells

Vitamin D- 600IUs

Vitamin D is critical for bone and teeth development, balanced hormones, and immune support. Additionally, adequate vitamin d levels is associated with lower likelihood of postpartum depression.

Iron- 27mg

Your body produces a lot more blood during pregnancy. Iron is necessary for making the extra blood a pregnant women needs and for the delivery of oxygen to your baby. Iron deficiency has been associated with adverse pregnancy outcomes including low birth weight, prematurity, and intrauterine growth restriction, IUGR.

Calcium- 1000mg per day

Calcium is essential for the formation of babies bones. If a pregnant women is not ingesting enough calcium then her body will pull from her own bones and teeth to make sure the developing baby is getting enough. This means weaker bones and teeth issues for mom in the long run.

Magnesium- 350-400mg

Magnesium supplementation during pregnancy can reduce the risk of preeclampsia and can result in higher birth weights.

Things to avoid in your prenatal vitamin

Food dyes

There should never be any food dyes in any of the supplements you take. They add no value to the product.


It is recommended to limit caffeine intake to no more than 200mg per day. If you are a coffee drinker, watch out for supplements with added caffeine that may be making you go over the recommended daily limit.

Folic acid

This is the synthetic form of vitamin B9, folate. It is not as easily absorbed and has to be converted to folate once ingested. If you have an MTHFR mutation or are a poor methylator you may not be converting this form sufficiently.


This is a cheaper synthetic form of B12 that has to be converted into methylcobalamin once it’s been ingested. If you are a poor methylator or have an MTHFR mutation, you will not convert this very well and can become deficient in B12.

High doses of Vitamin A

Vitamin A is teratogenic at high doses. Ask your doctor about any supplements you’d like to take with vitamin A in them to make sure that the dosage is safe for pregnancy.

Some things to keep in mind when it comes to prenatal vitamins

Prenatal vitamins are loaded with B vitamins which can make you nauseous if you take them on an empty stomach. Taking your prenatal vitamins after eating a meal can prevent nausea from ocuring.

You should always look for vitamin brands that are third party tested. This means that an independent company with no affiliation or benefits tested the product to ensure that the ingredients are all what they say they are.

Always ask your provider if you have questions about whether a supplement is a good and safe choice for you.


National Center on Birth Defects and Developmental Disabilities.

Nutrition during Pregnancy. American College of Obstetricians and Gynecologists.

Palmery M, Saraceno A, Vaiarelli A, Carlomagno G. Oral contraceptives and changes in nutritional requirements. Eur Rev Med Pharmacol Sci. 2013

Bastos Maia S, Rolland Souza AS, Costa Caminha MF, et al. Vitamin A and Pregnancy: A Narrative Review. Nutrients. 2019

Carlson SE, Colombo J, Gajewski BJ, Gustafson KM, Mundy D, Yeast J, Georgieff MK, Markley LA, Kerling EH, Shaddy DJ. DHA supplementation and pregnancy outcomes. Am J Clin Nutr. 2013

Abedi P, Bovayri M, Fakhri A, Jahanfar S. The Relationship Between Vitamin D and Postpartum Depression in Reproductive-Aged Iranian Women. J Med Life. 2018

Georgieff MK. Iron deficiency in pregnancy. Am J Obstet Gynecol. 2020 Oct;223(4):516-524. doi: 10.1016/j.ajog.2020.03.006. Epub 2020 Mar 14. PMID: 32184147; PMCID: PMC7492370.

Fanni D, Gerosa C, Nurchi VM, et al. The Role of Magnesium in Pregnancy and in Fetal Programming of Adult Diseases. Biol Trace Elem Res. 2021


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