Essential nutrients and vitamins in pregnancy


Pregnancy is a challenging time in terms of knowing what you can and cannot eat.  There are lots of nutrients needed to help your baby develop and keep you healthy, so pregnancy is an important time to put nutrition first.  Consuming a diet rich in essential vitamins and minerals is a key part of this, but can seem confusing – so let’s demystify this and help to get you started.


Folate is a type of B vitamin which has a role in metabolism and both red and white blood cell formation. During pregnancy, your folate requirements increase because of rapid cellular growth and development of your baby and your maternal tissues. Most importantly, folate can prevent Neural Tube Defects (NTD) during your baby’s development. During pregnancy, the Recommended Daily Intake (RDI) of folate is 600 micrograms per day which you can get from dietary sources such as legumes, eggs, leafy green vegetables and bananas.  However, it is recommended that you commence a prenatal multivitamin that contains folic acid (a form of folate) or a folic acid supplement at least one month prior to conception, as the neural tube develops early on in your baby’s life and can reduce risks of NTDs by up to 70%.  For most women the supplement dose prior to conception and during pregnancy is 400µg*[1] per day, but this can be higher for women who are overweight, smoke, have medical conditions such as Coeliac Disease or take particular medications such as those for seizures, so it’s a good idea to check your requirements with a prenatal dietitian.


Iodine is responsible for hormone production, metabolism and aids in healthy brain and nervous system development of your baby. During pregnancy, especially during the first 14-16 weeks, your baby is dependent on your thyroid hormone supply which means your demands for iodine increases. Adequate iodine consumption can reduce risks of physical impairment, brain damage and neonatal hypothyroidism in your baby, as well as reducing likelihood of stillbirths. The RDI during pregnancy for iodine is 220µg/day.   Iodine comes from the soil and see so you can get it from a wide range of foods.  However, if the soil in your area is depleted of iodine, it can be difficult to meet your increased needs during pregnancy.  In Australia, bread is fortified with iodised salt with iodised salt by law to assist with meeting iodine requirements.  It’s also beneficial to take a pregnancy multivitamin containing approximately ~150µg of iodine each day. However, if you have any thyroid conditions, make sure that you check with your doctor or dietitian before taking iodine supplements.


During pregnancy, your iron requirements increase to 27mg/day from 18mg/day due to a 50% increase  in blood to supply you and your baby with nutrients and oxygen. Haem iron from animal sources is readily absorbed in the body than non-haem iron, which comes from plant sources. This may be why some vegetarians struggle to meet their iron requirements. However, Vitamin C found in green, leafy vegetables, potatoes and tomatoes can help you to absorb non-haem iron.

Iron consumption is a major concern in pregnant women as only 20% meet the required iron stores (300-500mg) before entering pregnancy. This may lead to iron deficiency anaemia which can result in preterm labour, low birth weight and growth problems.  Therefore, it is vital to ensure you have adequate iron levels before and during your pregnancy.  However, high iron levels during pregnancy can also be problematic, so if you do have a history of low iron levels, suffer from severe nausea or vomiting in pregnancy, or follow a vegetarian diet, be sure to have your iron levels checked.

Vitamin D

Vitamin D helps to maintain levels of calcium and phosphate which helps build your baby’s muscles and bones. Although you can get some vitamin D through sunlight, it has been shown that even after 30 minutes of sunlight per day , it won’t be enough to meet the recommended pregnancy requirements.  Deficiencies of Vitamin D have been associated with preeclampsia and gestational diabetes for pregnant women and can also cause low birth weight and bone development problems in babies.  It’s beneficial to include foods rich in vitamin D such as eggs, cheese and salmon, as well as sunlight, to meet your RDI of 2000-4000 IU/day.  A dietitian will be able to advise you if you need to take a vitamin D supplement on top of your pregnancy multivitamin.

Omega 3

The main omega 3 fatty acid components are DHA (Docosahexaenoic acid) and EPA (Eicosapentaenoic acid). DHA is the main structural fat in the brain and the eyes, so is essential during pregnancy.  However, there are many other benefits of omega 3 DHA and EPA during pregnancy!  Studies have shown that DHA and EPA during pregnancy may reduce the risk of low birth weight babies, and may improve mental processing and hand-eye coordination later in life. Additionally, DHA may decrease the risk of postnatal depression, preeclampsia and preterm birth.  It’s recommended that you consume two to three serves of oily fish per week such as salmon or tuna to meet your omega 3 requirements of 115mg/day. While there is no evidence that all pregnant need to take omega 3 supplementation, it may be prescribed to you by your dietitian if you aren’t meeting the recommended intakes.

Vitamin B3

Also known as niacin, emerging evidence in animal studies suggests that vitamin B3 may potentially reduce the risk of miscarriages and birth defects however, further research is required.  Vitamin B3 also has an important role in your baby’s brain development.  Vitamin B3 can easily be acquired through the diet from wholegrains, cow’s milk, green vegetables and peanut butter.  Consuming a diet rich in these foods will help ensure you are meeting your RDI of Vitamin B3 which is 18mg/day.  Extra supplementation of this nutrient is generally not needed unless suggested by your dietitian.

Vitamin B12

Vitamin B12 is responsible for brain and nervous system functioning, cell metabolism and the cell growth of your baby. B12 is mostly found in animal products, so if you’re vegan or vegetarian, supplementation as prescribed by your dietitian may be required. Additionally, women who take metformin for diabetes, insulin resistance, polycystic ovarian syndrome or have had surgery on their stomach or bowel may be at risk of vitamin B12 deficiency and should consult a dietitian for more details. If deficiency is present, this may result in preterm birth, poor growth and insufficient brain development. Vitamin B12 works in conjunction with folate to prevent NTDs. The first 1000 days after conception are the most vital for your baby’s brain development which is why it’s important to ensure both B12 and folate levels are adequate. Regularly consuming foods such as fish, eggs and milk will help you achieve a diet rich in vitamin B12 and meet your RDI of 2.6 µg/day.


Evidence has shown that zinc during pregnancy can reduce preterm birth by 14% and has roles in making proteins, metabolism and immune function to ensure adequate growth of your baby. Low levels of zinc may result in reduced labour hormone circulation, increased infections and an increased risk of pre-term birth.  While taking a zinc supplement hasn’t been found to have significant benefits unless you’re deficient, eating a diet rich in zinc is important for your baby’s growth.  The RDI for zinc in pregnancy is 11mg/day – including plenty of foods such as legumes, seeds, cashew nuts and animal products like cheese, eggs, milk and meat will help ensure you and your baby are getting the zinc you need.


During pregnancy choline has a role in foetal growth and brain development. Choline works alongside Vitamin B12 and folate through metabolic processes which is why it’s important to ensure all these nutrients are adequate in your diet. Choline has also shown to play a role in NTDs. A study has shown that despite adequate levels of folate in pregnant women, NTDs may still occur if choline is insufficient. Consuming a diet rich in eggs, wholegrains, peanuts and lean chicken will help you meet your choline needs of 440mg/day.  In addition to this, a dietitian may also prescribe a choline supplement.

How do I choose a good quality supplement for pregnancy?

Although it is recommended that you obtain as much nutrition as possible for pregnancy by eating a variety of fruits, vegetables, wholegrains and proteins, it can be difficult to meet all your increased essential nutrient and vitamin needs.  To make it easier, a pregnancy multivitamin can be taken in conjunction with a healthy diet to meet your nutrient needs and help to keep you and your baby healthy.

It’s also important to keep in mind that more doesn’t necessarily mean it’s better for you. Having high doses of nutrients like Vitamins A, E, C, B6 and D may have detrimental effects on your baby’s health and development. But not to worry, your dietitian is there to guide you on what nutrients you may or may not need and will be sure to prescribe you with a multivitamin that best suits your personalised needs.  To ensure you are meeting your nutrient needs during your pregnancy, make an appointment with a dietitian today.


[1] *In Australia, 400 µg is considered adequate for the prevention of neural tube defects. Higher levels of folate can be tolerated, but my not be fully metabolised by some women due to their genetics.


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