Tips for Selecting A Prenatal Vitamin
While obtaining all essential nutrients from a whole-foods, balanced diet is the ideal approach to optimal wellness, various factors often make this impossible. Dietary restrictions, impaired digestion and/or absorption, poor soil quality, and limited access to fresh produce are all factors that contribute to the need for extra supports such as supplementation. The increased demand for nutrients during pregnancy alone often warrant a need for supplementation.
Supplementation is incredibly individual however, and should be based on each person’s unique needs and symptoms using testing whenever applicable. This is especially true when selecting a prenatal vitamin. Always seek the guidance of a nutrition professional to identify the right prenatal for your specific health circumstances. Below are a few things your practitioner should consider:
Vitamin A
Vitamin A comes in 2 forms: Preformed vitamin A (retinol; retinol esters) and provitamin A carotenoids (primarily β-carotene, α-carotene, and β-cryptoxanthin); both are lipid soluble and best absorbed in the presence of fat (1)
Provitamin A carotenes such as beta-carotene need to be converted to vitamin A; Preformed comes from animal sources and has higher bioavailability (1, 2) Some studies demonstrate “higher levels of supplementation of vitamin A, but not carotenoids, are needed during pregnancy” (6)
Very large doses of preformed vitamin A from animal sources or supplementation can be toxic and teratogenic; vulnerability highest during first 6 weeks gestation(1) there is no upper limit on beta-carotene or other carotenoids suggesting this form of vitamin A does not pose the same risk (6)
A food-based approach has been shown to effectively increase vitamin A status (2)
A balanced diet consisting of a combination of both preformed vitamin A and provitamin A carotenes along with proper assessment of circulating vitamin A levels is best practice
Work with a trained professional to identify conversion issues
Vitamin D
Vitamin D is also found in 2 forms; as cholecalciferol (D3) in humans and animals; as Ergocalciferol (D2) in plants
D3 is the preferred, more bioavailable form (5)
Can be synthesized when sun interacts with cholesterol in the skin-highly dependent on many factors however such as level of sun exposure, liver and kidney health, cholesterol intake, and nutrient deficiencies such as magnesium (3, 5) Very limited availability in food (5)
Vitamin D status is commonly low in pregnancy which is why there are specific recommendations for this period; WHO recommends 200 IU/Day; Institute of Medicine recommends 400 and 600 IU/day for the Estimated Average Requirement” and “Recommended Dietary Allowance” (RDA) respectively; Other studies suggest more than 1000 IU/day is necessary (3)
Safety is unclear; still Hollis et al demonstrated safety at 4000 IU/day in pregnancy (4)
Serum vitamin D evaluation is best practice to avoid over supplementation; vitamin D levels in prenatal vitamins vary and vitamin D may need to be supplemented in addition to some varieties
Folate
During pregnancy there is an increased demand for folate and this demand is critical during the early weeks of pregnancy when pregnancy may not be detected right away
A well-known link has been established between low levels of folate and neural tube defects
Folate deficiency increases homocysteine which is an independent risk factor for many pregnancy-related disorders including preeclampsia, preterm birth, placental abruption and gestational diabetes (6, 8)
Look for bioavailable, activated forms over synthetic forms; some synthetic vitamins such as folic acid have adverse associations such as Autism Spectrum Disorder (ASD) and allergies and may not be metabolized efficiently (6, 8)
While some people do better with the natural, methylated forms of folate due to genetic mutations impacting folate metabolism (7, 8), some people do not tolerate these well and require other formulations which a seasoned nutritional practitioner can offer guidance around
Iron
Requirements for absorbed iron increase gradually throughout gestation
Lab ranges look different in pregnancy compared to non-pregnant ranges due to the normal expansion of blood plasma compared to red blood cell mass (referred to as physiologic anemia of pregnancy) (9)
Best to have trained professional test CBC and full iron panel in 2nd trimester to assess iron needs-supplementation not always necessary
Considerable documentation exists linking chronic infection and inflammation with iron overload (10)
When indicated work with a nutrition professional to determine the best formof iron-some are less tolerated than others
Important to consider constipation, prior iron-anemia history, and additional factors that can impact iron tolerance and absorption
“A recent systematic review supports the concept that intermittent iron supplementation in pregnancy (2–3 times weekly, as opposed to daily) is as effective as daily supplementation, and associated with fewer side effects and presumably, higher compliance “ (9)
DHA and EPA
Omega 3 fatty acids docosahexanoic acid (DHA) eicosapentaenoic acid (EPA) play a critical role in fetal development especially brain and retinal development (11)
The balance of omega 3s to omega 6s is also important. Women in the west consume inadequate omega 3s in relationship to omega (6, 11)
DHA has been especially considered essential, especially during the 3rd trimester for brain and eye development and may be preventative against gestational diabetes, and preterm birth (6, 11)
EPA and DHA are both found in fish, but alpha-linolenic acid (ALA) is another omega 3 that is derived from some plant sources such as flaxseed that can be converted to DHA (11, 12)
Conversion of ALA to DHA and EPA is dependent on many factors and is limited (6) Relying on a plant-based diet alone may be insufficient
The current recommendations for fish intake during pregnancy is 2 servings of low-mercury fish per week in order to prevent mercury toxicity; this current recommendation for fish intake may not be enough to meet the needs of the developing fetus
Though no official intake requirements have been established, it is likely that pregnant women require more omega 3 fatty acids than their non-pregnant counterparts as is the case with most nutrients; some studies recommend supplementation of 600 mg of DHA per day and that EPA supplementation may benefit women who develop prenatal or postnatal depression (6, 11, 12)
The role of these nutrients at a glance:
Folate-decreases the risk for neural tube defects especially in early pregnancy and is protective against a number of other pregnancy-related conditions.
Vitamin D3-along with K2, calcium, and vitamin A, assists with mineralization of teeth and bone. Reduces the risk of preeclampsia, preterm birth, and infection (6)
B12-reduces preterm birth risk and is essential to nervous system development.
B6-adequate B6 may prevent morning sickness/nausea.
Iron-is needed to support increased red blood cell production (blood volume increases by 50%), placenta, and the fetal development
DHA-by third trimester baby’s brain is rapidly growing in size and one of the most abundant fats in the brain cells is the omega 3 fatty acid DHA. Fish is the most bioavailable source of DHA and the benefits are widely understood to outweigh the risk of mercury toxicity, however higher quality prenatal vitamins are beginning to include this now.
Final thoughts:
Vitamins and minerals have sophisticated, synergistic relationships and should be considered within this context. Both over and under consumption of certain nutrients can lead to an imbalance of others. Acquiring these from food is ideal, but not always sufficient especially when growing another human.
The above nutrients are by no means a complete list of what to look for in a prenatal vitamin. Choline, B12, and calcium are additional nutrients that are just as important as those listed above. The intention here is to shine light on the complexity of selecting a prenatal vitamin that meets a unique set of needs. Always consult your health care expert before integrating any supplementation. For more information on this topic refer to my post on Pregnancy and Nutrient Depletion.
Get tailored services and offerings for each trimester of pregnancy, with a professional trained to interpret labs specific to pregnancy by booking a free 30 minute consult with Carla!
References:
Gannon BM, Jones C, Mehta S. Vitamin A Requirements in Pregnancy and Lactation. Curr Dev Nutr. 2020 Aug 24;4(10):nzaa142. doi: 10.1093/cdn/nzaa142. PMID: 32999954; PMCID: PMC7513584.
Nankumbi J, Grant F, Sibeko L, Mercado E, O'Neil K, Cordeiro LS. Effects of Food-Based Approaches on Vitamin A Status of Women and Children: A Systematic Review. Adv Nutr. 2023 Nov;14(6):1436-1452. doi: 10.1016/j.advnut.2023.08.009. Epub 2023 Aug 25. PMID: 37634852; PMCID: PMC10721510.
Özdemir AA, Ercan Gündemir Y, Küçük M, Yıldıran Sarıcı D, Elgörmüş Y, Çağ Y, Bilek G. Vitamin D Deficiency in Pregnant Women and Their Infants. J Clin Res Pediatr Endocrinol. 2018 Mar 1;10(1):44-50. doi: 10.4274/jcrpe.4706. Epub 2017 Sep 13. PMID: 28901944; PMCID: PMC5838372.
Hollis BW, Johnson D, Hulsey TC, Ebeling M, Wagner CL. Vitamin D supplementation during pregnancy: double-blind, randomized clinical trial of safety and effectiveness. J Bone Miner Res. 2011 Oct;26(10):2341-57. doi: 10.1002/jbmr.463. Erratum in: J Bone Miner Res. 2011 Dec; 26(12):3001. PMID: 21706518; PMCID: PMC3183324.
Šimoliūnas E, Rinkūnaitė I, Bukelskienė Ž, Bukelskienė V. Bioavailability of Different Vitamin D Oral Supplements in Laboratory Animal Model. Medicina (Kaunas). 2019 Jun 10;55(6):265. doi: 10.3390/medicina55060265. PMID: 31185696; PMCID: PMC6631968.
Adams JB, Kirby JK, Sorensen JC, Pollard EL, Audhya T. Evidence based recommendations for an optimal prenatal supplement for women in the US: vitamins and related nutrients. Matern Health Neonatol Perinatol. 2022 Jul 11;8(1):4. doi: 10.1186/s40748-022-00139-9. PMID: 35818085; PMCID: PMC9275129.
Bakulski KM, Dou JF, Feinberg JI, Brieger KK, Croen LA, Hertz-Picciotto I, Newschaffer CJ, Schmidt RJ, Fallin MD. Prenatal Multivitamin Use and MTHFR Genotype Are Associated with Newborn Cord Blood DNA Methylation. Int J Environ Res Public Health. 2020 Dec 9;17(24):9190. doi: 10.3390/ijerph17249190. PMID: 33317014; PMCID: PMC7764679.
Carboni L. Active Folate Versus Folic Acid: The Role of 5-MTHF (Methylfolate) in Human Health. Integr Med (Encinitas). 2022 Jul;21(3):36-41. PMID: 35999905; PMCID: PMC9380836.
Means RT. Iron Deficiency and Iron Deficiency Anemia: Implications and Impact in Pregnancy, Fetal Development, and Early Childhood Parameters. Nutrients. 2020 Feb 11;12(2):447. doi: 10.3390/nu12020447. PMID: 32053933; PMCID: PMC7071168.
Wessling-Resnick M. Iron homeostasis and the inflammatory response. Annu Rev Nutr. 2010 Aug 21;30:105-22. doi: 10.1146/annurev.nutr.012809.104804. PMID: 20420524; PMCID: PMC3108097.
Greenberg JA, Bell SJ, Ausdal WV. Omega-3 Fatty Acid supplementation during pregnancy. Rev Obstet Gynecol. 2008 Fall;1(4):162-9. PMID: 19173020; PMCID: PMC2621042.
https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/#:~:text=DHA%20and%20EPA%20are%20present,the%20intestinal%20lumen%20%5B1%5D.