Knowing which prenatal supplement/s to buy can be a bit tricky. There is quite an array to choose from and they all differ ever so slightly. Some are marketed extremely well but this doesn’t mean that they are necessarily better than others. To help make choosing a supplement easier I’ve outlined a few important points below.

Aside from having an understanding of what to look for, it’s important to choose a supplement that best suits your individual needs. Below are a few considerations.

Firstly, there are two key nutrients that are highly beneficial to take via supplement form as a protective measure, these are folic acid and iodine.


Folic Acid

This is a very important B vitamin (vitamin B9). The synthetic form of this vitamin is folic acid (found in supplements and fortified food products) and the naturally occurring form is folate (found in certain foods).

For us women, this vitamin helps to optimize fertility by supporting healthy ovulation and therefore conception. For a baby, adequate amounts of this vitamin are crucial for helping to prevent congenital birth defects, primarily neural tube defects which are severe defects of the central nervous system the most common of which is spina bifida. We can significantly reduce the risk of neural tube defects by taking folic acid supplementation before trying for a baby as well as enjoying foods that are naturally high in folate.

Supplementation: A supplement of at least 400micrograms of folic acid a day is recommended for all women prior to trying for a baby and during the first trimester of pregnancy.

Now, here is an important consideration: When we consume folic acid our body needs to convert it into the active form often referred to as L-methylfolate or folinic acid. Not all individuals can easily do this, it is rare but some lack a particular enzyme that our body requires to activate folic acid. For this reason, it’s helpful to choose a supplement that is already in its active form as this way you know you’ll be able to absorb itOur body (thankfully) can easily convert folate (found in foods) into the active form so we don’t have to worry about dietary sources – all we need to do is enjoy them.

In terms of what supplement to choose there are several options. These include:

  • an individual folic acid supplement
  • a combined folic acid + iodine supplement or
  • a prenatal multivitamin that contains folic acid, iodine and all sorts of other goodies

Continue reading to work out what’s best for you. (Note: Some women require a higher dose of folic acid, for example, those with a past history of neural tube defects and those with Diabetes. If applicable to you it’s important to discuss supplementation with your GP.)

Dietary sources: The best dietary sources of folate include all dark green leafy vegetables (e.g. spinach, kale, silverbeet, beetroot leaves, chard), avocado, beetroot, brussel sprouts, asparagus, green beans, legumes, and lentils. Some food products are enriched with folic acid (e.g. breakfast cereals) so these provide another good boost. One thing that’s helpful to know too is that folate is heat-sensitive which means that when foods are cooked some folate is lost. For this reason, it’s important to enjoy some sources raw (and not only cooked).



Iodine is a mineral that we require for healthy thyroid function, healthy metabolism, and regulating certain processes that occur within our cells. For a growing baby, iodine plays a key role in the development of the nervous system and brain. This is why our requirements for iodine increase a little after we conceive.

Supplementation: While you’re trying for a baby it is recommended by the NHMRC that women take a daily supplement of 150micrograms. (Note however that if you have a thyroid disorder, appropriate supplementation should be discussed with your treating physician.)

Dietary Sources: Supplementation is highly recommended as it’s tricky to obtain adequate amounts via our diet. In Australia, the soil content of iodine is low so traces in our fresh produce are also low. For this reason, commercial bread (e.g. supermarket bread) is fortified with iodine to help meet our needs, but this only includes standard commercial bread, not organic, homemade, or artisan baked bread. However, I do still encourage enjoyment of artisan bread, organic and locally baked bread as there are benefits to choosing these too (i.e. they are delicious and purchasing such products helps to support our local economy). Other good sources of iodine include (safe amounts of) fresh fish and seafood, iodized sea salt and kelp (dried seaweed). (Regarding fish and seafood consumption, if unsure about what’s safe during preconception and pregnancy I’ll be sharing details in another blog post soon).


Other key vitamins and minerals 

All vitamins and minerals are important but the below are particularly important (aside from folate and iodine). Adequate dietary intake of the below (via the best dietary sources listed here) will protect your health but also support the healthy growth and development of a baby as soon as you conceive.

  • Vitamin B12 – red meat, fish, eggs, B12 fortified foods
  • B Group Vitamins – red meat, poultry, eggs, cheese, milk and soy milk, yoghurt, wholegrain bread and cereal, nuts and seeds, vegemite
  • Vitamin C – dark green vegetables, orange and red vegetables, fruits
  • Iron – red meat, fish, tofu, legumes, fortified foods, green leafy vegetables
  • Zinc – red meat, chicken, eggs, natural yoghurt, cheddar cheese, sardines, sunflower and pumpkin seeds, milk, tofu, oysters
  • Calcium – dairy, calcium-fortified plant-based milk, unhulled tahini, sesame seeds, green leafy vegetables, tofu
  • Omega 3 – Oily fish e.g. salmon, sardines, mackerel, anchovies, eggs, walnuts, flaxseeds, chia seeds
  • Magnesium – legumes, tofu, pumpkin seeds, avocado, dark chocolate/cacao/cocoa powder, nuts e.g. almonds
  • Selenium – brazil nuts, tuna, sardines, red meat, poultry, cashews, walnuts
  • Choline – eggs, seafood, beef, soybeans, chicken, mushrooms

So, do we need to be taking the above in supplement form?

The best starting point is to ensure a well-balanced diet. To find out whether you may benefit from boosting your intake of any of the above via supplementation it’s best to first have a blood test to check your blood levels and stores. Iron, vitamin D, vitamin B12, calcium, and zinc can all be checked via a blood test. However, certain nutrients are not so easy to measure and for this reason, we need to make sure we obtain adequate amounts via your diet.

If, after having a blood test, certain vitamin or mineral levels are low then supplementation is required which your GP will be able to advise you on. It’s also important to make sure you boost your dietary intake of rich sources such that you maintain healthy blood levels. An Accredited Practising Dietitian or Nutritionist will be able to provide you with guidance on this.

Prenatal multivitamins provide an array of vitamins and minerals so serve as a protective boost (most contain all of the above except for Choline this being a nutrient that has been newly discovered as playing an important part in preconception and pregnancy health).

For some women, a multivitamin is ideal but for others, a multi may not provide adequate amounts of certain nutrients so a few specific supplements may be required. The key message here is to have your blood levels checked first. If anything is low then speak with your GP about which supplements you require. If all looks healthy (and your diet is balanced and rich in all the important nutrients) then you have a few options as mentioned above – separate folic acid and iodine supplements, a combined folic acid and iodine supplement or a multivitamin. When choosing a supplement it’s worth reflecting on your diet (and a discussion with a dietitian can be really helpful here). For example, if your iron is healthy but you have had low iron in the past and/or you’re not a huge lover of red meat, chicken or fish and/or struggle to include lots of plant-based sources of iron then a multivitamin that provides a little more iron would be a great choice.


When should you start taking folic acid, iodine and other supplements (if required)?

It is advised that women should start taking folic acid and iodine supplementation (at the very least) 1 month prior to trying to conceive, however, most Dietitians and other health professionals highly recommend starting 3 months prior or earlier.

I always encourage clients to start taking a supplement at least 3 months prior. Starting early will ensure your blood levels and stores are topped up. It’s also beneficial to be enjoying a balanced and nourishing diet (rich in all the important nutrients) well before you start trying to conceive. When it comes to diet, like with other lifestyle factors such as physical activity and stress management, it’s helpful to start early so that you’re in a healthy and happy place once you conceive.

Soon I will be posting a separate blog post on fish safety. If you have any particular questions please don’t hesitate to contact me. Also, please note that the above summary is for general purposes only (all should not replace individualized advice provided by your Doctor or Dietitian).


Lara x

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