Preconception nutrients for women

Preconception is the time before your baby is conceived, and it is one of the most influential times on your future baby’s health. Your nutrition and health before conception has been shown to directly impact on the baby and getting this right can prevent conditions such as insulin resistance, obesity, autism, respiratory disorders and other cognitive conditions. It can even influence the future fertility of your child and even grandchildren! If you want to find out more about the importance of preconception care, read this blog here.

These are the most important nutrients a woman needs during preconception for a healthy pregnancy and baby.



Role in preconception and pregnancy

One of the most well known preconception vitamins, due to its role in the prevention of neural tube birth defects, miscarriage and Down’s syndrome. Folate is also extremely important for methylation, which is a biochemical process in the body involving production of DNA. Rapid DNA production begins in the embryo as soon as conception occurs and the neural tube closes by weeks 4-6 of pregnancy, therefore it is important folate is readily available before conception.

You may have been told by your doctor to take folic acid. Folic acid is actually slightly different to folate that is found in food, as it is a synthetic nutrient. And unfortunately for some women, they may not be able to metabolise folic acid due to a gene variation called Methylenetetrahydrofolate Reductase aka MTHFR. For women that have a history of infertility, miscarriage, or there is in your family, I encourage you to see your naturopath to be assessed if you have the MTHFR gene variation and other methylation issues. Make sure to see someone that is well versed in this area (my hand is here if you need). And if you do? Well, you will generally need to stay well clear of folic acid and instead use an active folate, which luckily are now readily available. And regardless of if you have a MTHFR variation or not, EVERYONE can benefit from consuming more food sources of folate such as leafy greens, avo, broccoli, citrus fruits and legumes.

Recommended intake: 500mcg/ day as an absolute minimum.

Food sources: dark leafy greens such as spinach, silverbeet (aim for 3 cups per day of mixed greens), kale, Avocado, broccoli, citrus fruits and legumes.



Iodine deficiency is rampant in the Western world. Mostly due to the fact that our diets are so deficient in this crucial nutrient. The main sources of dietary iodine are found in seafood and seaweed, and these foods are very low in a standard Australian diet.  Other causes for iodine deficiency are the fact our soil's content is low, and we are exposed to halogens such as fluoride, bromine and chloride. These compounds look similar in structure to iodine when in the body, and these minerals take all the seats up where iodine would normally be in the body's cells, so there is no room for iodine to be absorbed.  The government tried to overcome this, by making it compulsory for bread to be fortified with iodine, however, studies have shown this has not significantly improved iodine levels in our most at risk population- pregnant women.

Role in preconception and pregnancy

Iodine is a key component on thyroid hormone production. We need our thyroid functioning as is needed for ovulation and also in pregnancy. A subclinical thyroid dysfunction can double the risk of miscarriage. Iodine is also extremely important in the baby’ brain growth and a mild deficiency in a pregnant woman has been linked with a lower IQ in her future child. Severe deficiency can cause irreversible brain damage. (to find out more about the importance if iodine and thyroid health in pregnancy, visit here

The ideal intake of iodine really depends on your current level and thyroid function. So I suggest all woman be tested for iodine deficiency and have a full thyroid function test including TSH, T4, T3, TPO and TG autoantibodies (not just the standard TSH done by GPs as this tells very minimal information about your thyroid function) when starting preconception care. I test this in the clinic with a urinary iodine test and bloods for thyroid function.

Recommended dose: Minimum intake should be about 300mcg/ day and up to 1000-2000mcg in iodine deficient woman.

Food sources: seaweed, seafood, iodised salt (although I don’t recommend seafood or fish in preconception or pregnancy due to toxic and heavy metal contaminant concerns).  



Role in in preconception and pregnancy

Choline is a very important nutrient that I don’t think gets enough air time. Choline helps form DNA and cell structures which is very important in the preconception phase of a maturing an egg. It is also involved in the closing of the neural tube (as much as folate), so is important in preventing neural tube defects and needs to be sufficient before conceiving. It is also very important for foetal brain growth and supplementation of choline in pregnancy between 480- 930 mg has been correlated with a higher childhood IQ, compared to children born to choline deficient mothers. Research is currently in process to working out the ideal amount for pregnancy as the importance of choline in foetal growth has only been recently discovered. Current choline intake recommendations have been based on amounts required to prevent liver dysfunction, and were taken from studies done in men because no studies had investigated requirements during pregnancy. These levels were only recommending 50-100mg. New research suggests a minimum of 400mg/ day. I have looked at prenatal supplements available over the counter in pharmacies and supermarkets and some contain no choline! And if any, then in a very small amount which is why I recommend seeing a naturopath who can prescribe you a high dose prenatal.

Recommended dose: 400-900mg/ day

Food sources: eggs, grass fed beef, chickpeas, split peas, turkey, chicken breast, cauliflower. (Note: beef liver is a high source of choline but I do not recommend it in preconception care as also can be high in toxins if not organic and vitamin A that can cause birth defects if consumed in large amounts during pregnancy).

Docosahexaenoic Acid (DHA)

DHA is an essential omega-3 fatty acid found in seafood and fish. It can also be found in vegetarian algae sources; however, absorption of algae forms can be problematic with reduced availability so generally seafood is a better form. Unfortunately, with increased contamination in our oceans, seafood and fish are no longer a safe food to consume during preconception and pregnancy due to possible exposure to heavy metals such as mercury. This means a DHA deficiency can occur frequently in women.

Role in preconception and pregnancy

Children born to women with a DHA deficiency have been found to be at risk of sleep disturbances, nervous system disturbances, lower IQs, and increased blood pressure later in life. Many of these nervous system disorders and effects on brain development occur in the first trimester which is why it is crucial to supplement in preconception to ensure adequate amounts in early pregnancy. Women with a DHA deficiency during pregnancy are more likely to have preterm labour, hypertension and suffer postpartum depression.

For preconception omega 3 fatty acids, improve egg quality and hormone regulation, improving fertility outcomes.

Recommend dose: around 400-500mg DHA per day, often taken in conjunction with the other omega 3 fatty acid EPA.

Food sources: I am very hesitant to recommend seafood and fish food sources due to high risk of contamination. Best to supplement for this one.


Role in in preconception and pregnancy

Zinc is involved in over 300 processes in the body and is crucial for reproduction in men and women. A zinc deficiency can prevent maturation of an egg cell, fertilisation of an egg and also prevents implantation of a fertilised egg. In a study comparing a zinc deficient diet compared with zinc supplemented diet in mice, they found at day 10 of a pregnancy a 46% increase in the proportion of implantation sites containing either no embryo or an embryo without a heartbeat in the zinc deficient group compared to only 2% in the zinc replete group. There was also delayed closure of the neural tube in the zinc deficient group. Zinc deficiency has also been shown to lead to decreased embryo and placental weight and size and increased pregnancy loss. As these effects above occur in the maturation of the egg and very early in your pregnancy (not many women know at 10 days post fertilisation they are pregnant), it is so important to make sure you have adequate zinc intake before conceiving. If you are a vegetarian, vegan or you have been taking the oral contraceptive pill you are at increased risk of zinc deficiency. I often have my patients tested for zinc deficiency through a blood test.

 Recommended dose: 20-60mg, depending on the person and their needs

Food sources: red meat, beans, chicken, nuts, seeds, ginger

Vitamin D

Role in in preconception and pregnancy

Vitamin D is an extremely important nutrient in the body, so important that every single cell in our body requires vitamin D and it is involved in the regulation of over 2700 genes.  The general trend in literature is that a large majority of the world have vitamin D levels insufficient for optimal health. A healthy vitamin D level in pregnancy should be within the 100-150nmol/L range, however one study found 76% of women had levels under 80nmol/L and 23% had levels under 40nmol/L.

Children born to vitamin D Vitamin D deficient women have an increased risk of impaired lung development causing respiratory issues, short-sightedness, crooked teeth and decreased bone mass in their children. It has also been linked with decreased language development at the ages 5 and 10, multiple sclerosis and one study found an increased risk of adolescent eating disorders in children born to mothers with a vitamin D deficiency at 18 weeks pregnant.

For women, a vitamin D deficiency has been linked with miscarriage (47% of women with repeated pregnancy loss were vitamin D deficient), gestational diabetes, pre-eclampsia, post-natal depression, higher rate of Caesarean section, low birth weight babies and increase preterm births. Vitamin D deficiency also effects egg quality and is common in PCOS, both linked with infertility.

Recommended dose: this will depend on your current level of vitamin D, but a minimum supplement would be 1000IU. Remember you want your levels between 100-150nmol/L, not the medical range of 50nmol/L.

Food sources: The Sun!.. Exposure to the sun on your skin is important (without sunscreen). Also found fatty fish including sardine, salmon, herring, dairy and almond milk fortified with vitamin D, egg yolks.


Role in preconception and pregnancy

Magnesium is another common nutrient deficiency I find in people. This is because so many of our daily habits increase demand for magnesium from the body- Stress, caffeine consumption and exercise all decrease magnesium. Unfortunately our soils are also low in magnesium meaning sources from food can be poor. Magnesium has roles in over 300 enzymes in our body. Specifically, it’s importance in preconception and pregnancy is protein and carbohydrate metabolism to provide us nutrition from our food, energy production, DNA synthesis for healthy eggs and embryo growth, absorption and action of Vitamin D (see above), and bone. It is also important in preconception as aid oestrogen and progesterone production, decreases cortisol, and aids oestrogen metabolism. It also increases blood supply to the uterus, and can decrease risk of miscarriage (when taken with selenium). Magnesium adequacy in pregnancy has been shown to prevent preterm birth, low birth weight babies and small for gestational age babies. It can also possibly prevent metabolic syndrome in the unborn baby later in life. For women it can prevent gestational diabetes, preeclampsia and also reduces stress and anxiety during preconception and pregnancy.

Recommend dose: The minimum recommendation is 350mg, from a good magnesium source such as magnesium glycinate or citrate. Do not waste your money buying oxide or sulfate forms.

Food sources: leafy vegetables, whole grains, kelp, millet, tofu, rye, buckwheat, banana, avocado, apricots


Vitamin B12

Role in preconception and pregnancy

As discussed above we know folate as being one of the most important nutrients for prevention of neural tube defects and miscarriage, however B12 is just as important. This is because B12 is also used in the same methylation pathway that requires folate for preventing these conditions. It helps to make DNA for a growing embryo (crucial straight after conception) and also helps grow nerve cells and is involved in red blood cell production and oxygen transport (along with iron). Deficiency in a pregnant mother has been associated with early miscarriage, neural tube defects, intra uterine growth retardation, pre-eclampsia in the mother. It can also cause irreversible neurological and developmental delays in babies born to B12 deficient mothers.

Recommended dose: This will depend on your current blood level, and if you are a vegetarian or vegan who will need supplementation as all B12 food sources are of animal origin. A standard dose could range from 300-2000mcg.

Food sources: meat, dairy, eggs


Role in preconception and pregnancy

Iron deficiency is one of the most common nutrient deficiencies I see in women, and in the developing world has been called a global epidemic. Iron is crucial for oxygen transport and energy production in the body. It is needed for ovarian health and maturation of an egg prior to ovulation. It is also involved in DNA replication, which is occurring at a rapid rate in those first few days of conception.

In pregnancy, blood volume increases by 30% which requires a huge amount of iron. Iron deficiency in the first trimester has been shown to have a bigger impact on foetal growth than in 2nd and 3rd trimesters indicating the need for this nutrient to be at a correct level before conception. Babies born to iron deficient mothers are at risk of intra uterine growth retardation, premature birth and low birth weight babies. Babies also build up their stores of iron in the 3rd trimester for the first year of life, as breast milk contains little iron, and they often do not consume iron rich foods until 1 year old. Babies with low iron stores have been shown to have developmental difficulties including cognitive, social and emotional functions. Iron deficient pregnant women are at risk of increased perinatal infection, pre-eclampsia, and bleeding along with normal low iron symptoms including fatigue, fainting, heart palpitations, breathing and sleeping difficulties.

Recommend dose: this will depend on your level. A ferritin blood level should ideally be at 60-80ug/L before conceiving. A standard iron dose will be around 20-40mg/ day.

Food sources: Haem iron is found in meat, fish, chicken.  Non- haem iron is found in tofu, legumes, green vegetables, cashews and whole grains but is not as absorbable as haem sources.



Role in preconception and pregnancy

Selenium is a trace mineral used in many essential processes in the body. It is very important in the production of glutathione, our most powerful antioxidant, which aids in egg quality. Selenium is also needed in thyroid hormone production which is crucial for ovulation and also in pregnancy, specifically 1st trimester where a subclinical hypothyroid can double miscarriage rates. A selenium deficiency in a pregnant woman can increase gestational complications, miscarriage rates, and damage the nervous and immune systems of the foetus. It has also can cause to cause low birth weight babies.

Recommended dose: 50-100mcg/ day

Food sources: butter, brazil nuts, garlic, broccoli, onions and grains grow in selenium rich soil** (unfortunately Au soils are selenium deficient). Meat, chicken, fish, and eggs


The above are just some of the most important nutrients needed during preconception, and of course there are many more. A high quality prenatal multivitamin along with a good quality fish oil can offer the majority of these, and then additional supplements can be added where there are marked deficiencies ie iron, zinc. While I do recommend prenatal multivitamins in preconception and pregnancy, no supplement can out do a poor diet. Consuming a whole foods based diet (aka no junk food and refined sugars) with a good amount of protein, vegetables, fats, and whole grains, greatly increases your chances of not just conceiving, but creating a beautiful, healthy baby.

If you would like specific support with your health and preconception care, please contact with any queries you have or to make an appointment. Appointments can also be booked online here

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Tess x

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