Welcome back for part 2 of Choosing a Prenatal Supplement (you can read part one here)! In this post we will finish our discussion on prenatal supplement components and what to look for when selecting this important multivitamin from store shelves!

Omega 3

When looking for an omega 3 supplement, you want to make sure it contains two different omega 3 fatty acids: DHA (docosahexaenoic acid) and EPA (eicosopentaenoic acid). DHA is critical for fetal brain development. A pregnant woman’s body will transfer all of the DHA possible across the placenta to the fetus even if this means depleting the mother’s stores entirely. EPA is important in helping to prevent postpartum depression. Finally, omega 3 supplements have been shown to extend gestation and increase birth weight.

In randomized trials using a DHA supplement versus a placebo, the supplement improved infants’ visual acuity and growth as well as helped prevent maternal depression (Maizes, 2013)

When looking at the label, check to see that the fish oil is molecularly distilled, which means that heavy metal and polychlorinated biphenyl (PCB) contaminants that are present in many fish are removed. Look for a supplement with DHA and EPA adding up to 1000 mg and take with the largest meal of the day.

Nutrient dense food sources of DHA and EPA: mackerel, herring, salmon (wild pacific sockeye salmon is best), sardines, trout.

Don’t be fooled by foods such as ground flaxseed, walnuts, chia seeds, and flaxseed oil as being a good source of omega 3. These foods contain the form of omega 3 known as ALA (alpha-linolenic acid), which must be converted in the body into DHA and EPA to have the benefits listed above. Unfortunately, the conversion rate from ALA to DHA/EPA is believed by researchers to be less than 1% in healthy individuals.

A Canadian survey of 176 pregnant women revealed that while 90 percent were taking multivitamins, none were taking the vitamins with omega 3, and only 11 percent were taking separate omega 3 supplements (Maizes, 2013)

Vitamin D

A large percentage of women living in northern latitudes have low vitamin D status, this is a nutrient of significant importance. See my post on vitamin D here for food sources and additional information on the importance of the sunshine vitamin.

There is evidence in animal studies and some from human trials that fertility is impaired if the mother has a low vitamin D level. She will have a harder time getting pregnant and once pregnant, she will have an increased risk of preeclampsia and gestational diabetes (Maizes, 2013)

The Institute of Medicine considers vitamin D doses of up to 4,000 IU/day to be safe. My recommendation to clients is to get his/her vitamin D levels checked based on a supplement dosage of 1000-2000 IU/day and then have levels checked once every 6-12 months after until consistently in the normal range.

It is worth noting that many multivitamins, including prenatal multivitamins, only contain 200 IU of vitamin D. If you already have an inadequate vitamin D status (anything less than 50 ng/L according to the vitamin D council) than 200 IU/day is unlikely to correct this inadequacy.

Nutrient dense food sources of vitamin D: milk, yogurt, egg yolk, salmon, mackerel, herring, trout.


Calcium is needed during pregnancy to help with baby’s bone development (particularly in the third trimester) and to keep mother’s bones strong during this time as well. Women need 1,000-1,300 mg of calcium during pregnancy and breastfeeding. I suggest focusing on food first for calcium however, many women struggle to get in enough calcium to meet pregnancy and post-partum needs. If choosing to supplement, it is recommended to split up calcium supplements because we cannot absorb more than approximately 500 mg of calcium at one time.

Nutrient dense food sources of calcium: green vegetables, milk products, salmon, sardines.

Vitamin E

Pregnant women use vitamin E for preventing complications in late in pregnancy due to high blood pressure.

Check the label on your prenatal multivitamin for dl alpha tocopherol. Dl alpha tocopherol is the synthetic form of vitamin E and indicates that the product is poor. What you should see is d-alpha tocopherol or even better, 200-400 IU of mixed tocopherols and tocotrienols. Synthetic forms of vitamin E are generally derived from petroleum products and are not as bioavailable as natural vitamin E.

Vitamin B12

Women at particular risk of low vitamin B12 levels include: vegan or strict vegetarians, women taking proton pump inhibitors or other acid blockers (think TUMS, Rolaids, etc.) or have been on the birth control pill for several years. Women with type 2 diabetes mellitus or polycystic ovarian syndrome who are prescribed metformin are also at risk of low vitamin B12 levels, due to the depletion that this drug causes.

Vitamin B12 is essential during pregnancy for DNA synthesis and low levels of this vitamin increases risks of repeated miscarriage and birth defects.

The recommended daily intake of vitamin B12 is 2.4 mcg during perception and 2.6 mcg during pregnancy. You may notice that many vitamin B12 supplements on store shelves are quite high in comparison to the recommended dietary allowance. This is due to the fact that absorption of 100% of what is in the supplement does not occur. For example, a supplement with 1,000 mcg of oral vitamin B12 leads to absorption of about 20 mcg.

Nutrient dense food sources of vitamin B12: animal meat (particularly organ meat), fish, milk products and fortified almond milk, nutritional yeast.

Additional vitamins and trace minerals
Trace minerals in a multivitamin should include copper, zinc, magnesium, potassium, and calcium.

Just remember: taking a supplement never takes the place of consuming nutrient dense foods. Think of a supplement as what it is – a supplement to your currently awesome, nutrient dense diet. 

Until next time nutrient seekers..

Yours in health,








Maizes V (2013). Be fruitful: the essential guide to maximizing fertility and giving birth to a healthy child.

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