As a Registered Dietitian-Nutritionist, I often promote obtaining your nutrients from your food rather than supplements. However, during the prenatal time your body has an increased demand for many nutrients that are crucial for your health and baby’s proper development that can be difficult to get from food alone. Selecting a high quality prenatal vitamin is so important, but it can be a challenge to know what to look for with so many options on the market.

Below I outlined several key nutrients of importance during pregnancy and recommended amounts – so that you can use this as a guide when selecting a prenatal vitamin. It is highly recommended to start taking your prenatals before you are pregnant at the time you are trying to conceive, as it can take several months to build up your stores of some nutrients.

This guide is not designed to replace personalized medical advice and does not include ALL nutrients needed, but rather those that are most critical and often under consumed. Always check with your healthcare provider prior to starting to any supplement to determine what is best for you based on your individual needs.

The research is constantly changing on our diet during pregnancy. Based on the research we know thus far, here are some key nutrients to look for in your vitamin supplements and recommended daily amounts:

Folate – Daily Needs – 600 mcg

Most of us refer to folate as “folic acid,” the man-made form of folate that most often is seen in supplements and fortified grains like bread and ready-to-eat cereals. However, up to 60% of the population actually has a genetic mutation of an enzyme (called MTHFR) and cannot properly absorb folic acid. It is important to check with your doctor to see if you have this, because if so then you would want to select a prenatal containing the absorbable form – called “methylfolate” or “l-methylfolate.”

Folate or folic acid is crucial to baby’s development to prevent against neural tube defects, cleft lip and palate, heart abnormalities, and anemia. Adequate folate intake during pregnancy may also play a role in preventing obesity in baby later in life.

Natural sources of folate in your diet are liver, leafy greens, lentils, beans, and broccoli.

Summary – Look for at least 600 mcg of folate in your supplement.

Iron – Daily Needs – 27 mg

Iron needs are 1.5x higher during pregnancy to support increased blood flow and transfer of oxygen to you and baby, as well as to meet the demands of your growing baby and placenta. Iron also helps you to maintain the energy you need throughout your pregnancy as well as after baby is born. So important for an expecting mama!

There are two types of iron – heme and non-heme iron. Heme iron is found in animal sources – such as liver, red meat, chicken, and seafood . Non-heme iron is found in plant sources – such as beans, lentils, and green leafy vegetables. Non-heme iron sources are not absorbed very efficiently in our bodies, so if you are a vegetarian it is crucial to obtain additional iron from a supplement to meet your needs.

Summary – Look for at least 27 mg of iron in your supplement.

Vitamin D – Daily Needs – 4000 IU

Vitamin D is essential for proper bone development and reducing pregnancy complications such as preeclampsia, low birthweight, and gestational diabetes. There is also research on the role of Vitamin D in reducing the risk of postpartum depression, an increasingly common issue that is likely more widespread than we realize.

The current RDA (Recommended Dietary Allowance) is set at 600 IU, or International Units, for the general population. However, several studies have shown this is likely not enough during pregnancy. A study on pregnant women who consumed up to 7000 IU/day had no adverse health effects.

Vitamin D deficiency is very common even in the general population, and it is very difficult to get enough from our diet alone especially without adequate sun exposure. Majority of our Vitamin D is made from sun exposure (up to 90%), and for many of us depending on where we live and our ability to get outside, it may not be realistic to get enough. Although I am a huge proponent for getting outside whenever possible – for many reasons!

Because many prenatal supplements do not contain enough vitamin D (unfortunately not all the research has caught up yet to the manufacturers), you may need a separate supplement based on your blood levels. Look for Vitamin D3 which is the active, absorbable form and always take with a meal containing fat. Vitamin D is a fat-soluble vitamin meaning it needs fat to be properly absorbed in your body. Your Vitamin D levels may not be routinely checked unless you have signs of a deficiency, so be sure to ask your doctor.

Food sources of Vitamin D are sockeye salmon, light tuna (not albacore as it is high in mercury), and fortified milk, orange juice, eggs, and yogurt.

Summary – Look for a Vitamin D supplement containing at least 4000 IU. Take with a meal or snack containing fat. Ask your physician to check your Vitamin D levels (called 25-OH Vitamin D).

DHA – Daily Needs – Minimum 300 mg


DHA is the best absorbed form of the Omega-3 fats and is found in animal foods such as fatty fish, pasture-raised chickens and fortified eggs. It is essential during pregnancy as well as when breastfeeding. DHA has a major role in proper brain and vision development in baby. It also protects the brain from inflammation and damage and can reduce the risk of postpartum depression.

It is possible to get enough from your diet if you are consuming fatty fish and DHA-fortified eggs regularly, but if you aren’t then a supplement is necessary. Most prenatal vitamins will not contain the minimum amount of DHA because it is difficult to fit in the capsule. Look for a separate DHA supplement that also contains EPA, which is another type of fat that assists in the absorption of DHA and its ability to transfer through the placenta to baby.

Some studies have shown a dose up to 2,200 mg is safe and resulted in significantly higher hand-eye coordination test scores in children up to age 4.

Summary – look for a DHA supplement containing at least 300mg DHA as well as EPA to help with absorption and DHA transfer to the placenta.

Choline – Daily Needs – Minimum 450 mg


Choline is a critical nutrient during the prenatal time that has only recently become more well known. It is a type of fat that is vital for fetal brain development, placental health, and the prevention of neural tube defects. In this way it acts similar to folate. Like with folate, women who have the MTHFR gene mutation may not be able to properly absorb choline and may need it in higher doses than the 450 mg minimum. In fact, some studies have shown improvements in maternal and child health outcomes in daily doses of 930mg.

Egg yolks and liver are the highest food sources of choline. Therefore if you are a vegetarian or do not eat these foods regularly, it is likely you are not getting enough. In a supplement, look for choline bitartrate or sunflower lecithin.

Summary – Look for a supplement with at least 450mg of choline, specifically choline bitartrate or sunflower lecithin. If you are diagnosed with the MTHFR mutation or follow a vegetarian diet, ask your healthcare provider if you need a higher dose.

Magnesium – Daily Needs – 300 mg

According to recent research, 48% of Americans are magnesium deficient. It is likely even more common than this during pregnancy. Magnesium is involved in our vascular health and helps to prevent common pregnancy complications such as preeclampsia and gestational diabetes. If you have ever dealt with painful leg cramps, otherwise known as “charliehorses,” these often result from a magnesium deficiency. Magnesium has also been shown to have the potential benefit in reducing morning sickness, so even more incentive to make sure you’re getting enough!

When choosing a magnesium supplement (as prenatals may not contain enough), look for magnesium glycinate as this is often the most well tolerated form and the least likely to cause digestive upset.

Good food sources of magnesium are seaweed, leafy greens, pumpkin seeds, Brazil nuts, sunflower and sesame seeds, chia, avocados, and unsweetened cocoa power.

Summary – Look for magnesium glycinate in a supplement as is the most absorbed form.

Prenatal Vitamin Summary

The list above highlights the most critical nutrients that many women tend to not get enough of in their diets, but there are many others that are not on this list. Speak to a Registered Dietitian or Healthcare Provider about the best option for your needs and preferences based on your specific nutrient levels. If you have additional questions or are feeling overwhelmed, please comment below or schedule a free call with me.

References

  1. Nichols, Lily. Real Food for Pregnancy.  USA: Nichols, 2018.
  2. Greenberg, James A, and Stacey J bell. “Multivitamin supplementation during pregnancy: emphasis on folic acid and L-methylfolate.” Reviews in Obstetrics and Gynecology 4.3-4 (2011): 126.
  3. Bello, Jennifer K., et al. “Pregnancy Weight Gain, Postpartum Weight Retention, and Obesity.” Current Cardiovascular Risk Reports 10.1 (2016): 1-12.
  4. Alavi, N., et al. “Comparison of national gestational weight gain guidelines and energy intake recommendations.” Obesity Reviews 14.1 (2013): 68-85.
  5. Lain, Kristine Yl, and Patrick M. Catalano. “Metabolic changes in pregnancy.” Clinical Obstetrics and Gynecology 50.4 (2007): 938-948.
  6. Lee, Joynce M et al. “Vitamin D deficiency in a healthy group of mothers and newborn infants.” Clinical Pediatrics 46.1 (2007): 42-44.
  7. Viljakainen, HT et al. “Maternal vitamin D status determines bone variables in the newborn.” The Journal of Clinical Endocrinology & Metabolism 95.4 (2010): 1749-1757.
  8. Innis, Sheila M. “Dietary (n-3) fatty acids and brain development.” The Journal of Nutrition 137.4 (2007): 855-859.