Prenatal Vitamins

Last Updated: March 12, 2024

Prenatal supplements, also known as prenatal vitamins, are frequently used by women before conception and throughout gestation. Their purpose is to guarantee that both the expectant mother and the developing fetus obtain the necessary quantity of vital nutrients. They usually contain folic acid, iron, and other micronutrients, but the composition varies from brand to brand.

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Prenatal Vitamins is most often used for

What are prenatal supplements?

Prenatal supplements, also known as prenatal vitamins, are supplements commonly taken by women during the pre-conception period and throughout pregnancy to ensure that both the mother and the fetus receive the appropriate amount of essential nutrients. Despite being referred to as “prenatal vitamins”, they typically include a combination of 3 or more vitamins and minerals. These may encompass vitamins vitamin B1, vitamin B2, B3, vitamin B6, vitamin B12, C, D, E, and K, along with folic acid, iodine, magnesium, iron, copper, zinc, selenium, and sometimes additional components like omega-3.[3][4]

It is generally recommended for all pregnant women to take at least iron and folic acid to support proper fetal development, and to prevent anemia and other complications during pregnancy. However, especially in low- and middle-income countries, women may experience multiple micronutrient deficiencies, and thus a prenatal multi-micronutrient supplement might be more suitable.[5]

What are the main benefits of prenatal supplements?

During pregnancy, when nutritional requirements are higher, micronutrient deficiencies can have adverse health and development consequences (e.g., preterm birth, small for gestational age, low birth weight). In many countries, it is recommended that women take prenatal supplements during pregnancy, typically containing a combination of iron and folic acid plus other vitamins and minerals.[4]

One meta-analysis, which included women of different gestational ages in low-income and middle-income countries, revealed that supplementation with a multiple-micronutrient (MMN) supplement (i.e., one containing 3 or more micronutrients) reduced the risk of low birth weight infants and the risk of babies considered small for gestational age more than supplementation with just iron and folic acid (IFA); this effect was especially pronounced with supplements containing more than 4 micronutrients. MMN supplementation also lowered the risk of stillbirth and the occurrence of diarrhea in children. Moreover, MNN slightly increased maternal and child serum retinol levels, slightly increased maternal zinc and vitamin B12 levels, and improved executive function scores in children, compared to IFA. However, no difference was noted for all other studied outcomes, including maternal or perinatal mortality, risk of miscarriage, risk of congenital anomalies, preterm births, risk of C-section, child general intelligence, motor functioning, verbal comprehension, or language.[4] While studies such as this one suggest benefits from taking an MMN prenatal supplement instead of one that only contains folic acid and iron, variations in methods and interventions used, such as supplement composition, may need to be addressed before drawing generalized conclusions.

Whether MMN supplements are more beneficial than just IFA in upper-middle-income and high-income countries remains unclear: it likely varies depending on the intake of essential micronutrients from the diet.[6]

What are the main drawbacks of prenatal supplements?

Prenatal supplements are generally considered safe and well-tolerated when taken at the recommended dosage. However, it’s important not to exceed the recommended daily intake during pregnancy, as higher doses of certain vitamins and minerals may be harmful to the fetus (e.g., iron, folic acid, zinc). Studies specifically addressing the risks of exceeding the upper limit (UL) of these micronutrients during pregnancy are lacking, except for vitamin A. Excessive intake of vitamin A (above 3000 μg)[7] during pregnancy is known to have teratogenic (i.e., birth-defect-causing) effects.[1][2] In some prenatal supplements, vitamin A is substituted with beta-carotene, which is converted into vitamin A naturally by the body as required and does not appear to be teratogenic at high doses.[8]

Another potential side effect of taking prenatal vitamins and minerals is constipation, primarily caused by iron.[9]

How do prenatal supplements work?

Prenatal supplements contain a blend of different vitamins, minerals, and other nutrients, all of which are known to play a crucial role in various biological reactions and metabolic activities, thereby promoting maternal health and supporting fetal growth. Therefore, there is more than one mechanism of action involved, depending on the micronutrient composition of each supplement. For detailed information on how each micronutrient functions in the body, please refer to the individual pages dedicated to those specific nutrients.

What are other names for Prenatal Vitamins?
Note that Prenatal Vitamins is also known as:
  • Maternity vitamins
  • Pregnancy supplements
  • Antenatal vitamins
  • Prenatal vitamins
  • Prenatal multivitamins
  • Gestational vitamins
  • Preconception vitamins
  • Maternal health supplements
  • Prenatal minerals and nutrients
  • Multiple-micronutrient supplements
Dosage information

The dosage of prenatal supplements can vary by brand, so it’s advisable to refer to the instructions provided on the manufacturer’s website or supplement package.

During pregnancy, it’s important to avoid exceeding the recommended dosage. Consuming certain vitamins and minerals in excess amounts may pose risks to the fetus.[1][2]

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Update History
2024-03-12 00:30:03

Full FAQ and database update


We fully updated this page and have several brand-new FAQs about this topic.

  1. ^Gernand ADThe upper level: examining the risk of excess micronutrient intake in pregnancy from antenatal supplements.Ann N Y Acad Sci.(2019-May)
  2. ^Olson JM, Ameer MA, Goyal AVitamin A ToxicityStatPearls.(2023-01)
  3. ^Vitamin supplementation in pregnancy.Drug Ther Bull.(2016 Jul)
  4. ^Keats EC, Oh C, Chau T, Khalifa DS, Imdad A, Bhutta ZAEffects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review.Campbell Syst Rev.(2021-Jun)
  5. ^Keats EC, Haider BA, Tam E, Bhutta ZAMultiple-micronutrient supplementation for women during pregnancy.Cochrane Database Syst Rev.(2019-Mar-14)
  6. ^Gernand AD, Schulze KJ, Stewart CP, West KP, Christian PMicronutrient deficiencies in pregnancy worldwide: health effects and prevention.Nat Rev Endocrinol.(2016-May)
  7. ^Adams JB, Kirby JK, Sorensen JC, Pollard EL, Audhya TEvidence based recommendations for an optimal prenatal supplement for women in the US: vitamins and related nutrients.Matern Health Neonatol Perinatol.(2022-Jul-11)
  8. ^Bastos Maia S, Rolland Souza AS, Costa Caminha MF, Lins da Silva S, Callou Cruz RSBL, Carvalho Dos Santos C, Batista Filho MVitamin A and Pregnancy: A Narrative Review.Nutrients.(2019-Mar-22)
  9. ^Trottier M, Erebara A, Bozzo PTreating constipation during pregnancy.Can Fam Physician.(2012-Aug)
  10. ^Pharoah P, Buttfield IH, Hetzel BSNeurological damage to the fetus resulting from severe iodine deficiency during pregnancy.Int J Epidemiol.(2012-Jun)
  11. ^Rastogi MV, LaFranchi SHCongenital hypothyroidism.Orphanet J Rare Dis.(2010-Jun-10)
  12. ^Han X, Ding S, Lu J, Li YGlobal, regional, and national burdens of common micronutrient deficiencies from 1990 to 2019: A secondary trend analysis based on the Global Burden of Disease 2019 study.EClinicalMedicine.(2022-Feb)
  13. ^Karrar SA, Hong PLPreeclampsiaStatPearls.(2024-01)
  14. ^Sanam Behjat Sasan, Farnaz Zandvakili, Nasrin Soufizadeh, Elaheh BaybordiThe Effects of Vitamin D Supplement on Prevention of Recurrence of Preeclampsia in Pregnant Women with a History of PreeclampsiaObstet Gynecol Int.(2017)
  15. ^Kerry Richard, Olivia Holland, Kelly Landers, Jessica J Vanderlelie, Pierre Hofstee, James S M Cuffe, Anthony V PerkinsReview: Effects of maternal micronutrient supplementation on placental functionPlacenta.(2017 Jun)
Examine Database References
  1. Infant Birth Weight - Keats EC, Oh C, Chau T, Khalifa DS, Imdad A, Bhutta ZAEffects of vitamin and mineral supplementation during pregnancy on maternal, birth, child health and development outcomes in low- and middle-income countries: A systematic review.Campbell Syst Rev.(2021-Jun)
  2. Infant Birth Weight - Ramakrishnan U, Grant FK, Goldenberg T, Bui V, Imdad A, Bhutta ZAEffect of multiple micronutrient supplementation on pregnancy and infant outcomes: a systematic review.Paediatr Perinat Epidemiol.(2012-Jul)
  3. Autism Risk - Friel C, Leyland AH, Anderson JJ, Havdahl A, Borge T, Shimonovich M, Dundas RPrenatal Vitamins and the Risk of Offspring Autism Spectrum Disorder: Systematic Review and Meta-Analysis.Nutrients.(2021-Jul-26)