Introduction
Supplements for pregnancy play a vital role in supporting the health of both the mother and the developing baby. While a balanced, varied diet is the best way to obtain necessary nutrients, prenatal vitamins can help fill nutritional gaps and ensure adequate intake of key vitamins and minerals (Mayo Clinic, n.d.; American College of Obstetricians and Gynecologists [ACOG], 2021).
Pregnant women have increased nutritional needs to support the growth and development of their baby. However, meeting these requirements through diet alone can be challenging, especially if the mother experiences morning sickness or has dietary restrictions. This is where supplements for pregnancy come in, providing a convenient way to ensure optimal nutrition during this crucial time.
In this comprehensive article, we will explore the essential nutrients needed during pregnancy, the role of prenatal vitamins, and the importance of consulting with healthcare providers before starting any supplement regimen. We will also discuss supplements to avoid or use with caution and the significance of a balanced diet in pregnancy nutrition.
Essential Nutrients During pregnancy
Folic Acid (Folate)
Folic acid, also known as folate, is a B vitamin that plays a crucial role in reducing the risk of neural tube defects (NTDs) such as spina bifida and anencephaly (Czeizel et al., 2013). The neural tube is the precursor to the baby’s brain and spinal cord, and NTDs occur when the neural tube fails to close properly during early pregnancy (Imbard et al., 2013). Research has shown that supplementing with folic acid before conception and during the first trimester can reduce the risk of NTDs by up to 70% (Viswanathan et al., 2017).
The recommended daily intake of folic acid for pregnant women is 400-800 micrograms (mcg) per day, starting at least one month before conception and continuing through the first trimester (World Health Organization [WHO], 2012). Good dietary sources of folate include dark green leafy vegetables, citrus fruits, legumes, and fortified cereals (Tamura & Picciano, 2006). However, it can be challenging to obtain sufficient amounts of folate through diet alone, which is why folic acid supplementation is highly recommended for all women of reproductive age (Centers for Disease Control and Prevention [CDC], 2020).
In addition to preventing NTDs, folic acid also supports the overall growth and development of the fetus (Bailey et al., 2015). Adequate folate intake has been associated with a reduced risk of preterm birth, low birth weight, and certain congenital heart defects (Feng et al., 2015; Fekete et al., 2012; Li et al., 2013). Furthermore, folic acid plays a vital role in the production of red blood cells and the synthesis of DNA and RNA (Greenberg et al., 2011).
Iron
Iron is an essential mineral that is crucial for the production of haemoglobin, the protein in red blood cells that carries oxygen to the body’s tissues (Abbaspour et al., 2014). During pregnancy, the demand for iron increases significantly to support the growth and development of the fetus and placenta, as well as to expand the mother’s blood volume (Bothwell, 2000). Inadequate iron intake can lead to iron deficiency anaemia, which is associated with an increased risk of preterm birth, low birth weight, and perinatal mortality (Haider et al., 2013).
The recommended daily intake of iron for pregnant women is 27 milligrams (mg) per day, which is almost double the amount required for non-pregnant women (Institute of Medicine [IOM], 2001). Good dietary sources of iron include lean red meat, poultry, fish, legumes, and fortified cereals (Hurrell & Egli, 2010). However, many women struggle to meet their iron requirements through diet alone, particularly if they follow a vegetarian or vegan diet (Pawlak et al., 2016). In these cases, iron supplementation may be necessary to prevent deficiency.
prenatal vitamins typically contain a significant amount of iron, but some women may require additional supplementation based on their individual needs (Milman, 2012). Healthcare providers can assess iron status through blood tests and recommend the appropriate dosage of supplemental iron if needed (Pavord et al., 2012). It is important to note that excessive iron intake can also be harmful, so it is crucial to follow the guidance of a healthcare professional when considering iron supplementation (Schümann et al., 2007).
Calcium and Vitamin D
Calcium and vitamin D are essential nutrients for the development and maintenance of strong bones and teeth (Holick, 2007). During pregnancy, the growing fetus requires a significant amount of calcium to support skeletal development (Kovacs, 2001). If maternal calcium intake is insufficient, the body will draw calcium from the mother’s bones to meet the needs of the fetus, which can increase the risk of osteoporosis later in life (Kalkwarf et al., 1997).
The recommended daily intake of calcium for pregnant women is 1,000-1,300 mg per day, depending on age (IOM, 2011). Good dietary sources of calcium include dairy products, leafy green vegetables, and calcium-fortified foods (Weaver et al., 1999). prenatal vitamins typically contain some calcium, but additional supplementation may be necessary to meet the increased demands of pregnancy (Hacker et al., 2012).
Vitamin D plays a crucial role in calcium absorption and metabolism (Holick, 2007). Adequate vitamin D status is important for both maternal and fetal health, as deficiency has been associated with an increased risk of preeclampsia, gestational diabetes, and low birth weight (Aghajafari et al., 2013; Wei et al., 2013). The recommended daily intake of vitamin D for pregnant women is 600 international units (IU) per day (IOM, 2011).
The primary source of vitamin D is sunlight exposure, but dietary sources include fatty fish, egg yolks, and fortified dairy products (Holick, 2007). However, many women do not obtain sufficient vitamin D through sunlight exposure or diet, particularly those living in northern latitudes or with darker skin pigmentation (Mulligan et al., 2010). In these cases, vitamin D supplementation may be necessary to maintain adequate levels during pregnancy (Hollis & Wagner, 2017).
Iodine
Iodine is an essential trace element that is necessary for the production of thyroid hormones, which play a critical role in fetal brain development (Zimmermann, 2009). Iodine deficiency during pregnancy can lead to intellectual disability, stunted growth, and even miscarriage or stillbirth (Pearce et al., 2016). The recommended daily intake of iodine for pregnant women is 220 mcg per day (WHO, 2007).
Good dietary sources of iodine include iodised salt, seafood, and dairy products (Zimmermann, 2009). However, iodine content in foods can vary widely depending on the iodine content of the soil in which they are grown (Pearce et al., 2016). In regions where iodine deficiency is common, iodine supplementation may be necessary to ensure adequate intake during pregnancy (Zimmermann & Boelaert, 2015).
prenatal vitamins often contain iodine, but the amount can vary between brands (Leung et al., 2013). It is important for pregnant women to discuss their iodine status and potential need for supplementation with their healthcare provider, as excessive iodine intake can also be harmful (Pearce et al., 2016).
Omega-3 Fatty Acids (DHA and EPA)
Omega-3 fatty acids, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are essential for fetal brain and eye development (Koletzko et al., 2008). DHA is a major structural component of the brain and retina, and adequate intake during pregnancy has been associated with improved cognitive function and visual acuity in infants (Innis, 2008).
The primary dietary source of DHA and EPA is fatty fish, such as salmon, sardines, and anchovies (Kris-Etherton et al., 2009). The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women consume 2-3 servings of low-mercury fish per week to obtain adequate amounts of omega-3 fatty acids (ACOG, 2015). However, some women may not consume enough fish due to personal preferences or concerns about mercury contamination (Taylor et al., 2016).
In these cases, omega-3 fatty acid supplementation, particularly in the form of DHA, may be beneficial (Carlson et al., 2013). prenatal vitamins may contain DHA, but the amount can vary widely between brands (Greenberg et al., 2008). The optimal dosage of DHA supplementation during pregnancy is not well established, but most studies have used doses ranging from 200-800 mg per day (Koletzko et al., 2008).
It is important to note that while omega-3 fatty acid supplementation can be beneficial, it should not replace a balanced diet that includes a variety of nutrient-dense foods (Coletta et al., 2010). Pregnant women should discuss their individual needs and potential benefits of omega-3 fatty acid supplementation with their healthcare provider.
Supplements to Avoid or Use with Caution
Vitamin A
Vitamin A is an essential nutrient that plays a role in fetal development, particularly in the formation of the eyes, lungs, and heart (Clagett-Dame & Knutson, 2011). However, excessive vitamin A intake during pregnancy, particularly in the form of retinol, can be teratogenic and lead to birth defects (Rothman et al., 1995). The recommended daily intake of vitamin A for pregnant women is 770 mcg of retinol activity equivalents (RAE) per day (IOM, 2001).
Good dietary sources of vitamin A include liver, dairy products, and orange and yellow fruits and vegetables (Trumbo et al., 2001). prenatal vitamins typically contain vitamin A, but it is important to choose a formulation that contains beta-carotene rather than retinol (Strobel et al., 2007). Beta-carotene is a precursor to vitamin A that is found in plant sources and is considered safe during pregnancy (Tanumihardjo, 2011).
Pregnant women should avoid supplements that contain high doses of retinol, as well as liver and liver products, which are extremely high in vitamin A (Bastos Maia et al., 2019). It is also important to be cautious of topical retinoids, such as those found in some acne medications, as they can be absorbed through the skin and potentially cause harm to the fetus (Chien et al., 2016).
Herbal Supplements
Herbal supplements are often perceived as natural and safe alternatives to conventional medications, but their use during pregnancy can be risky (Dugoua, 2010). Many herbal supplements have not been thoroughly studied in pregnant women, and some may contain compounds that can be harmful to the fetus (Tiran, 2003).
Some herbal supplements that should be avoided during pregnancy include:
- Black cohosh: This herb is often used to treat menopausal symptoms but has been associated with an increased risk of miscarriage and preterm birth (Dugoua et al., 2006).
- Dong quai: This Chinese herb is sometimes used to treat menstrual cramps but can stimulate uterine contractions and lead to miscarriage (Circosta et al., 2006).
- Goldenseal: This herb is often used to treat digestive issues and boost the immune system but can cross the placenta and potentially harm the fetus (Yarnell & Abascal, 2009).
- Yohimbe: This African herb is sometimes used as an aphrodisiac but can cause high blood pressure, heart palpitations, and other adverse effects (Ernst, 2002).
Pregnant women should be cautious of any herbal supplement and discuss their use with a healthcare provider before consuming them (Kennedy et al., 2016). Some herbal teas, such as ginger and peppermint, may be safe in moderation but should still be used with caution and under the guidance of a healthcare professional (Heitmann et al., 2013).
The Role of a Balanced Diet in pregnancy Nutrition
While supplements can help fill nutritional gaps, a balanced and varied diet should be the foundation of pregnancy nutrition (Marangoni et al., 2016). Eating a wide range of nutrient-dense foods from all food groups can help ensure that both the mother and the growing fetus receive the necessary nutrients for optimal health and development (Procter & Campbell, 2014).
The MyPlate website, created by the United States Department of Agriculture (USDA), provides a helpful visual guide for creating healthy, balanced meals during pregnancy (USDA, 2021). The MyPlate recommendations for pregnant women include:
- Fruits: 2 cups per day, focusing on whole fruits rather than juices.
- Vegetables: 3 cups per day, including a variety of colors and types.
- Grains: 6-8 ounces per day, with at least half being whole grains.
- Protein: 6-7 ounces per day, choosing lean meats, poultry, fish, beans, and nuts.
- Dairy: 3 cups per day, opting for low-fat or fat-free options.
In addition to these food groups, pregnant women should also focus on consuming healthy fats, such as those found in avocados, nuts, seeds, and olive oil (Coletta et al., 2010). Staying hydrated by drinking plenty of water and limiting sugary drinks and caffeine is also important (Bardosono et al., 2016).
Pregnant women with specific dietary restrictions, such as vegetarians or vegans, may need to pay extra attention to certain nutrients that may be lacking in their diets (Penney & Miller, 2008). For example, vegetarians and vegans may need to focus on consuming plant-based sources of iron, calcium, and vitamin B12, or consider supplementation under the guidance of a healthcare provider (Piccoli et al., 2015).
Monitoring Nutrient Levels and Addressing Deficiencies
Throughout pregnancy, healthcare providers may recommend blood tests to monitor nutrient levels and identify any deficiencies (Hovdenak & Haram, 2012). Common nutrient deficiencies during pregnancy include iron, vitamin D, and iodine (Darnton-Hill & Mkparu, 2015).
If a deficiency is detected, healthcare providers may recommend specific dietary changes or supplementation to address the issue (Gernand et al., 2016). For example, if an iron deficiency is identified, the healthcare provider may recommend increasing the intake of iron-rich foods, such as lean red meat, poultry, fish, and legumes, or prescribing an iron supplement (Milman, 2012).
It is important for pregnant women to attend regular prenatal check-ups and follow the advice of their healthcare providers regarding nutrient monitoring and supplementation (Kirkham et al., 2005). Addressing nutrient deficiencies early can help prevent potential complications and ensure the best possible outcomes for both the mother and the baby (Darnton-Hill & Mkparu, 2015).
Conclusion
In conclusion, supplements for pregnancy play a vital role in supporting the health and development of both the mother and the growing baby. While a balanced, varied diet is the foundation of optimal nutrition during pregnancy, prenatal vitamins can help fill nutritional gaps and ensure adequate intake of essential nutrients.
Key nutrients such as folic acid, iron, calcium, vitamin D, iodine, and omega-3 fatty acids are crucial for fetal growth and development. Folic acid helps prevent neural tube defects, while iron supports the production of haemoglobin and prevents anaemia. Calcium and vitamin D are essential for the development of strong bones and teeth, and iodine plays a critical role in fetal brain development. Omega-3 fatty acids, particularly DHA, are important for brain and eye development.
However, it is important to be cautious of certain supplements, such as high doses of vitamin A, which can be teratogenic, and herbal supplements that may have not been thoroughly studied in pregnant women. Consulting with healthcare providers is essential to determine the most appropriate supplement regimen based on individual needs and potential deficiencies.
Ultimately, the goal of prenatal nutrition is to support the healthy growth and development of the baby while maintaining the well-being of the mother. By focusing on a balanced diet, taking appropriate supplements as recommended by healthcare professionals, and monitoring nutrient levels throughout pregnancy, women can help ensure the best possible outcomes for themselves and their growing babies.
Key Highlights and Actionable Tips
- Eat a varied diet with adequate amounts of key nutrients like folate, iodine, protein, iron, calcium, vitamin D, and omega-3 fats
- Take a daily pregnancy supplement containing at least 500 micrograms of folate, 150 micrograms of iodine, and 400 IU of vitamin D
- Vegetarians and vegans should ensure they get enough vitamin B12 from supplements or fortified foods
- Aim to include protein-rich foods at each meal, such as meat, fish, eggs, dairy, legumes, nuts, and tofu
- Eat iron-rich foods and consider an iron supplement if your levels are low
- Have 2-3 serves of calcium-rich foods daily, like dairy, canned fish with bones, firm tofu, or calcium-fortified plant milks
- Eat fish 2-3 times a week for omega-3 fats, but avoid high-mercury varieties
- Practice food safety to reduce the risk of listeria, toxoplasmosis, and salmonella infections
How much extra energy do I need during pregnancy?
During pregnancy, you need some additional energy to support your baby’s growth and development. In general, you need around 340-450 extra calories per day in the second and third trimesters. However, the exact amount varies depending on factors like your pre-pregnancy weight, physical activity level, and whether you’re carrying twins or multiples. Focus on eating a balanced diet with a variety of nutritious foods rather than just eating more.
Should I take a prenatal vitamin as well as eating a healthy diet?
Yes, it’s recommended to take a prenatal vitamin supplement in addition to eating a healthy diet during pregnancy. While a varied diet can provide many essential nutrients, some key vitamins and minerals like folate, iodine, and vitamin D are difficult to get enough of from food alone. A daily prenatal supplement helps ensure you meet your increased requirements and supports your baby’s healthy development.
Are there any herbal supplements I should avoid during pregnancy?
Some herbal supplements can be harmful during pregnancy and are best avoided. These include supplements like black cohosh, dong quai, and goldenseal, which may stimulate uterine contractions or have other dangerous side effects. It’s important to check with your healthcare provider before taking any herbal or nutritional supplements during pregnancy, as they can interact with medications or have unintended consequences.
How can I meet my increased iron needs in pregnancy?
pregnancy increases your iron requirements to support your baby’s growth and your expanded blood volume. To boost your iron intake, include iron-rich foods in your diet, such as red meat, poultry, fish, legumes, green leafy vegetables, and fortified cereals. Combining these foods with vitamin C sources like citrus fruits can enhance iron absorption. If blood tests show your iron levels are low, your doctor or midwife may recommend an iron supplement.
What food safety precautions should I take while pregnant?
Practicing good food safety is crucial in pregnancy to minimise the risk of infections like listeria, toxoplasmosis, and salmonella. Some key precautions include: thoroughly washing fruits and vegetables, cooking meat and eggs until well done, avoiding unpasteurised dairy products and soft cheeses, reheating processed meats until steaming hot, and promptly refrigerating leftovers. It’s also important to wash your hands well and avoid contact with cat litter or soil that may contain toxoplasmosis parasites.
References
American College of Obstetricians and Gynecologists. (2021). Nutrition during pregnancy. https://www.acog.org/womens-health/faqs/nutrition-during-pregnancy
Healthline. (2024). Supplements during pregnancy: What’s safe and what’s not. https://www.healthline.com/nutrition/supplements-during-pregnancy
March of Dimes. (2020). Vitamins and other nutrients during pregnancy. https://www.marchofdimes.org/find-support/topics/pregnancy/vitamins-and-other-nutrients-during-pregnancy
Mayo Clinic. (n.d.). pregnancy week by week. https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-vitamins/art-20046945
National Health Service. (2023). Vitamins, supplements and nutrition in pregnancy. https://www.nhs.uk/pregnancy/keeping-well/vitamins-supplements-and-nutrition/
pregnancy, Birth and Baby. (2023). Vitamins and supplements during pregnancy. https://www.pregnancybirthbaby.org.au/vitamins-and-supplements-during-pregnancy
The Women’s Hospital. (n.d.). Food & nutrition in pregnancy. https://www.thewomens.org.au/health-information/pregnancy-and-birth/a-healthy-pregnancy/food-nutrition-in-pregnancy
