Julia Dixon Dietitian + Nutritionist

“What prenatal supplements do you recommend?” is one of my most asked questions in clinic, on instagram and from friends.

So first up, unless you are my client and I know your history, I can’t recommend a prenatal supplement for you. There is no one size fits all supplement, despite what supplement companies would like you to think. Shameless plug, but click to become a client >>

Pretty much every prenatal supplement on the market is different. They contain different nutrients, vitamins and minerals, at different quantities and in different chemical forms. What you need, will be very specific to you.

I will forever and always recommend booking a consultation with a prenatal and fertility dietitian before buying a prenatal supplement. A fertility dietitian will help you choose the right supplement and optimise your diet, -read more about diet and fertility here>> so you get more nutrition bang for your buck.

It is so important to consider your medical history, current diet & preferences, medications, symptoms and about a million other things. Also where you are on your conception journey. Is your priority optimising egg and sperm health, or implantation or managing PCOS or endometriosis and so forth. All of which will dictate what supplement will work best for you.

So knowing all of that, these are some key prenatal nutrients to consider. However, this article is not intended to replace your healthcare providers’ advice.

Folate

Let’s dive right into one of the most debated nutrients (in my world anyway). Folate, also known as vitamin B9, is essential for healthy cell division and DNA synthesis.

It is a well established fact that folate adequacy in early pregnancy reduces the risk of neural tube defects (NTD). The evidence is so strong, the Australian Government introduced mandatory folic acid fortification of flour for bread-making in 2009. Note: organic and gluten free breads are exempt from fortification.

Folic acid is the synthetic form of folate. Folate is the food form of folate. Folic acid is used in fortified bread flour and in many prenatal supplements on the market. Then we have folinic acid and 5MTHF (5-methyltetrahydrofolate), which are the active forms of folate.

Folate chemical forms in supplements are hotly debated in the science and healthcare community at the moment. All NTD risk reduction research to date is based on folic acid use. But emerging research suggested methylated forms are better absorbed, especially for the portion of the population with an MTHFR gene mutation (more on this another day).

I have undertaken additional training specifically for folate supplementation, and I can tell you now, recommendations will vary by practitioner. The best form for you will be totally dependent on you, your genetics, and your needs.

But something we always seem to forget is that folate in its most active form is already available in food. And it was in food way before it was in supplements 😉 Leafy greens, legumes like kidney beans, black beans and lentils, fruits, veggies and whole grains are great sources of folate.

Women	Pregnancy	Breastfeeding
400ug	600ug	500ug

Iodine

Iodine maintains normal thyroid function as the key cofactor for the synthesis of thyroid hormones (T3 and T4). Thyroid hormones are responsible for metabolism and growth, amongst other crucial functions.

In pregnancy, adequate maternal iodine intake is responsible for the healthy development of baby’s brain and nervous system. And for the prevention of a serious condition called cretinism. Evidence has also shown iodine deficiency in early pregnancy can negatively impact baby’s longterm IQ also. This means iodine requirements increase in pregnancy – and they increase again if breastfeeding.

Now, that all sounds scary, and I don’t meant to scare you! Please know that most prenatal supplement on the market will contain iodine. And the Australian Government introduced mandatory iodine fortification of iodised salt for bread making in 2009. This was based on population studies indication low iodine in women of childbearing age.

However, data continues to suggest iodine inadequacy is common amongst women and pregnant women. This is attributed to a variety of reasons including depleted iodine concentrations in the food supply and changes to dairy production. Suffice to say, iodine is a nutrient to know about, and probably supplement prenatally.

Good dietary sources of iodine include eggs, seaweed (ie: kelp, nori, kombu, and wakame), seafood and breastmilk.

Women	Pregnancy	Breastfeeding
150ug	220ug	270ug

Vitamin D

The sunshine vitamin is most famous for its role in aiding calcium absorption. Which is very important in pregnancy for baby’s skeletal development. But, this fat soluble vitamin is so much more.

Evidence associates adequate serum (blood level) vitamin D with increased fertility rates. As well as a reduced risk of pregnancy related high blood pressure (pre-eclampsia) and gestational diabetes. Serious talk here, there’s more at play than just vitamin D when it comes to fertility and conditions of pregnancy. But if your vitamin D levels are low in your prenatal blood test, it is a nutrient worth topping up. A prenatal and fertility dietitian can advise a safe regime is levels are low.

While foods like eggs, salmon, sun-soaked mushrooms contain some vitamin D, the best source is the sun. Exactly how much sun exposure is needed depends on the UV index, season, skin type, country you’re in and so forth.

I am not including national recommendations for vitamin D because:

• A recommended daily intake (RDI) has not been established, rather there is a adequate intake (AI) in place
• The values can become confusing as they are expressed in different units to supplement labels

A discussion with your GP or dietitian for a personalised approach based on your levels here is highly recommended.

Choline

Choline is kinda the new kid (nutrient) on the block in the prenatal world. You might see it listed on the ingredient label of newer prenatal supplements. But rarely in amounts shown to have a clinical benefit.

Choline plays many important physiological roles including gene expression, cell membrane signalling, metabolism and early brain development. Evidence also suggests, like folate, choline is crucial while baby’s neural tube is developing in early pregnancy.

It is not a vitamin or a mineral, but it is sometimes recognised as an essential vitamin-like nutrient. This is because the body can make some choline but not enough, with diet forming part of achieving nutritional adequacy.

Because choline is stored in the liver, organ meat is a good dietary source. Other dietary sources include meat, legumes, fish and mushrooms. You can obtain about half of the daily adequate intake recommendations from 2 eggs.

The RDI for this nutrient is currently poorly understood (much like most things nutrition related). National guidelines state limited data is available to establish and RDI, with an AI set at 440mg per day. However, growing evidence suggests higher doses may be warranted in pregnancy.

Omega-3

My all time favourite polyunsaturated fatty acid (PUFA). Omega-3 EPA & DHA (eicosapentaenoic acid & docosahexaenoic acid respectively) are associated with improved conception rates, reduced preterm labour, baby’s healthy brain development, improved postpartum maternal mood. The research here is strong, but not loud enough for my liking. With many prenatal supplements not containing enough (or any) DHA/EPA.

Dietary omega-3s come from marine sources, namely oily fish like salmon, mackerel, trout, sardines, herring & tuna. Dietary plant-based omega-3s come in the form of Alpha-linolenic acid (ALA for short). ALA is a precursor to the formation of DHA and EPA in the body. But the conversion is underwhelming with only 0.5-10% converted into the active form. This means you would need to eat a LOT of flax and chia seeds to obtain enough DHA/EPA. Oily fish is an excellent source, aim for 2-3 serves per week.

I am not including the RDI for omega-3 because Australian national guidelines have yet to establish one. There is an AI, however it does not necessarily reflect optimal intakes with current evidence suggesting higher levels to be beneficial. Particularly in pregnancy when baby’s omega-3s must come from the maternal (mum’s) diet. I am sorry for sounding like a broken record here, but it is another reason why a dietitian should be recommending your supplement regime.

Iron

Introducing the mineral with the highest deficiency risk amongst women who menstruate. This mineral is responsible for oxygen transport across the entire body. And as the oxygen delivery service, iron is essential for the healthy development of baby’s organs and brain.

Daily iron requirements for women of childbearing age at 18mg/day are more than double mens’ at 8mg/day. This jumps to 27mg/day in pregnancy to accomodate additional blood volume and baby’s growth.

The body does become better at absorbing iron as each trimester progresses. But it is still very hard to meet the intake recommendations. This is why almost all prenatal supplements will contain iron.

Now supplemental iron is a really good way to increase your levels. But they are well known to (sometimes) cause gastrointestinal symptoms like constipation. This is where you want to look at the 3 Fs (fibre, fluids and fitness). You can download my free high fibre recipe book here.

Some good dietary iron haem (meat) sources include meats (choose lean cuts), liver, seafood & eggs.

And non-haem (non-meat) sources include tofu, seaweed, green leafy veggies, legumes, apricots, fortified whole grains and breakfast cereals.

*Please note, non-haem sources are not absorbed as efficiently as haem iron. So if you follow a vegan or vegetarian diet, these tips may help improve absorption:

• Pair plant-based iron foods with vitamin C like a lentil salad with a lemon juice dressing to improve absorption
• Caffeine may inhibit iron absorption, so leave about an hour gap between your coffee/tea/beverage between high iron meals and supplements
• Similarly, calcium and zinc can inhibit iron absorption, reducing those interactions is helpful (a dietitian can help with this)

Women 19-50yrs	Pregnancy
18mg	27mg

Vitamin B12

Vitamin B12 (or cobalamin) is a water soluble nutrient responsible for DNA synthesis, formation of red blood cells and the development or brain and nerve cells. All critical things when growing a baby.

Anyone following a vegetarian or vegan diet or with stomach acid complications is at high risk of deficiency. Certain medications and high-dose supplements can reduce levels of vitamin B12 in the body also. So it is one to note, especially preconception and during pregnancy.

Most prenatal supplements on the market will contain vitamin B12 as either cyanocobalamin, or the active form methylcobalamin.

Meat, seafood and eggs form good dietary sources of vitamin B12. Dietary plant-based sources however are hard to come by. Which is why if you follow a vegetarian or vegan diet, you will know about Vitamin B12. Including fortified plant milks, nutritional yeast and some mushrooms and maybe supplementing is crucial.

Women	Pregnancy	Breastfeeding
2.4ug	2.6ug	2.8ug

Other Nutrients

This post was getting rather long, if you made it to the end – thank you!

I have only scratched the surface here when it comes to prenatal nutrients. Zinc, copper, selenium, the B vitamin family, vitamins A, C, E and K, copper, magnesium, manganese, antioxidants, inositols and on and on should be considered based on your diet, history and about a million other things I ask my clients. Suffice to say, it is nuanced and your regime should be tailored to you.

As with everything, there can be too much of a good thing, with upper limits of nutrients established to prevent toxicity. Prenatal supplements can contain high quantities of vitamins and minerals. Paired with additional supplements – or even a protein powder containing vitamins and minerals, you can exceed these upper limits.

So always chat to your healthcare team to establish which prenatal supplements are right for you. Or book a 1:1 consult with a dietitian trained in fertility and prenatal nutrition (like me :))