Pregnancy – avoiding nutrient deficiencies

When you are pregnant or breastfeeding, you need to eat healthily so you get the nutrients your baby needs to grow well and for your own wellbeing. Healthy eating during pregnancy can help lower the risk of health conditions, including:

• blood pressure-related disorders such as pre-eclampsia, pregnancy-induced high blood pressure and eclampsia
• gestational diabetes. 

Eating healthily can also reduce the risk of childbirth complications.

The key nutrients that you need in pregnancy are:

• folate/folic acid
• iodine
• iron
• calcium
• vitamin C
• vitamin D
• vitamin B12.

This vitamin is needed to make blood cells and new tissue. During pregnancy, you need more folic acid. Lack of folic acid has been linked with neural tube birth defects (NTDs) such as spina bifida. The risk of having a child with these birth defects is low and can be reduced by taking a folic acid tablet.

• Take a folic acid-only tablet (0.8 mg) daily for 4 weeks (1 month) before you might become pregnant through to 12 weeks (3 months) after actually becoming pregnant.
• If you find out that you are pregnant and you haven’t been taking a folic acid tablet, start taking tablets straight away and continue until the 12th week of your pregnancy.
• Folic acid tablets are available on prescription from your doctor or midwife, which is usually the cheapest option, or they can be bought over the counter at a pharmacy.

Read more about folate/folic acid.

This is an essential nutrient required in small amounts to support normal growth and development, including brain development. It is important that unborn babies receive enough iodine. 

• Take a daily iodine-only (0.150 mg/150 μg) tablet from a month before the start of your pregnancy until you stop breastfeeding.
• Iodine tablets are available on prescription from your doctor or midwife, which is usually the cheapest option, or they can be bought over the counter at a pharmacy.
• Choose foods that are good sources of iodine such as well-cooked seafoods, milk, eggs, some cereals and commercially made bread (excluding organic and unleavened bread as they are not required to be made with iodised salt). If you use salt, choose iodised salt.

Read more about iodine.

It is important that you maintain your iron levels during pregnancy and breastfeeding. Your body needs more iron during pregnancy and breastfeeding to make up for higher blood volume and to support healthy baby development. Low iron levels (iron deficiency) also cause anaemia, which would make you more fatigued and tired than is expected during pregnancy. Severe iron deficiency can lead to low birthweight, pre-term birth and poor child development. Talk to your doctor, midwife or dietitian if you suspect you may have iron deficiency as there are iron supplements available on prescription. Read more about iron.

Ensure you have a balanced diet with plenty of calcium-rich foods, eg, milk and milk products, nuts, tinned or well-cooked bony fish, dried fruit. During pregnancy and breastfeeding, you should have 4 serves of calcium-rich foods per day to help help keep your bones healthy. Read more about calcium.

Vitamin C is important to help absorb iron. This is especially helpful if you are a vegan or vegetarian. Vitamin C can be found in a variety of vegetables and fruits.

Vitamin D is essential for strong bones, muscles and overall health. It is particularly important in pregnancy, where vitamin D is needed for your baby’s bone and teeth development.

Some foods contain vitamin D but most of vitamin D is made in your skin when it is exposed to sunlight. You are at higher risk of having low vitamin D levels (vitamin D deficiency) if you have darker skin, have limited sun exposure, stay indoors a lot due to poor health, live in the South Island, have liver or kidney disease or are on certain medicines that affect vitamin D. If you at higher risk of vitamin D deficiency, talk to your doctor, midwife or dietitian to find out whether you need to take any vitamin D supplements.

Read more about vitamin D and pregnancy.

Vitamin B12 is important for normal blood and nerve function. If you are pregnant or breastfeeding, you need enough vitamin B12 for your own body and your baby’s development. Vitamin B12 can be found in animal foods and fortified foods such as breakfast cereals, non-dairy milk and Marmite. Read more about vitamin B12. 

Like other adults, the 4 main food groups that you need to eat during pregnancy are:

• vegetables and fruits
• grain foods, mostly whole grain and those naturally high in fibre
• milk and milk products, mostly low and reduced fat
• protein food such as legumes (beans, lentils and peas), nuts, seeds, fish and other seafood, eggs, poultry and/or red meat with the fat removed.

Read more about food groups and serving size.

If you are eating a wide variety of foods, you are unlikely to need supplements, except for:

• folic acid-only tablet – 800 micrograms per day from 4 weeks before you are pregnant until the 12th week of your pregnancy
• iodine tablet – 150 micrograms from the start of your pregnancy until you stop breastfeeding.

It is not recommended you take supplements other than folic acid and iodine (such as multivitamins for pregnancy) and you must only take supplements on the advice of your doctor or midwife. Talk to your doctor, midwife or dietitian if you think you may have any nutrient deficiencies, eg, if you are a vegan, your healthcare team may advise you take vitamin B12 supplements.

If you are a vegan or vegetarian, you can still get the key nutrients required for pregnancy from your food, but you might need to look a little more closely to make sure.

Here are some tips to help you get the nutrients you need:

• Take iron-fortified foods to make sure you are getting enough iron during pregnancy or breastfeeding.
• Drink plant-based milk fortified with vitamin B12 and calcium, ideally soy milk as it is higher in energy and protein.
• Eat plenty of vegetables and fruits as they contain vitamin C which helps to absorb non-haem iron available in plant-based foods at the same time.
• Talk to your doctor, midwife or dietitian to find out whether you need vitamin B12 supplements as vitamin B12 is only found in animal foods and fortified foods such as breakfast cereal, plant-based milks, nutritional yeast and Marmite.

If you are unsure which foods to eat or are worried that you may have any nutrient deficiencies, talk to your doctor, midwife or ask your healthcare team to refer you to a dietitian.