If you are pregnant, or planning a pregnancy, you need to be careful about what you eat. This includes taking vitamins or any other type of supplements. Some help keep you and your baby healthy while others do more harm than good.

It's always best to check with your midwife, doctor or dietitian before taking any vitamins or supplements.

What nutrients do I need in pregnancy?

Good nutrition in pregnancy is vital for the healthy growth and development of your baby. Your body needs a variety of nutrients for good health, such as:

• carbohydrates
• fats
• fibre
• protein
• vitamins and minerals

While you are pregnant, you don't need to eat for 2. But you do need to eat enough nutrients to meet both your and your baby's needs.

What are vitamins, minerals and supplements?

Vitamins and minerals are nutrients that your body needs in small amounts to work properly.

Apart from vitamin D, which your skin makes from sunlight, most of the vitamins you need come from food.

When you're pregnant, you need more of some vitamins and minerals, including:

• Calcium and vitamin D — to make sure your baby has healthy bones.
• Folate — folate (folic acid) helps stop neural tube defects.
• Iodine — is needed for brain and nervous system development.
• Iron — helps form red blood cells and stops anaemia.
• Omega-3 — these polyunsaturated fats support healthy brain, nerve and eye development in your baby.
• Protein — to form new body tissues.

Dietary supplements are products designed to give you nutrients that might be missing from your diet.

Do I need to take supplements?

Having a healthy diet is important and should give you the nutrients you need. Dietary supplements contain nutrients that can fill a gap in your diet. However, it's recommended that all pregnant women in Australia take a:

• folic acid supplement
• iodine supplement
• vitamin D supplement

Folic acid

Folate is found naturally in green leafy vegetables. It's also added to food, such as bread and breakfast cereals, as folic acid.

In Australia and New Zealand, folic acid is added to all bread-making flour (except for organic flour). However, the best way to guarantee you get enough folic acid is to take a daily folic acid supplement.

You should take at least 0.5mg of folic acid for at least one month before a planned pregnancy. A baby's growth is very quick in the first weeks of life — often before you know you are pregnant.

Continue taking this supplement for the first 3 months of pregnancy to reduce your baby's risk of neural tube defects such as spina bifida.

Your doctor may recommend a higher dose of folic acid (5mg) if you:

• have diabetes
• are obese
• take anticonvulsant (epilepsy) medicine
• have a member of your family affected by a neural tube defect
• are at risk of poor food absorption

Iodine

Iodine is important for your baby's brain development. An iodine supplementation of 150mcg per day is recommended pre-pregnancy, during pregnancy and while breastfeeding.

Vitamin D

Vitamin D is needed for your body to take-up and use calcium. You should also take a vitamin D supplement of 400IU to 600IU per day during pregnancy.

Iron

In your second and third trimesters, you will have increasing iron demands.

Ask your midwife or doctor if you need iron supplements. Iron supplementation is not necessary in every pregnancy.

Calcium

Calcium is important in pregnancy for your baby's growth. However, there is no need for extra calcium supplementation beyond the normal recommended dietary intake. This is because your body adapts to make more efficient use of your own calcium.

Do I need to take a multivitamin in pregnancy?

A multivitamin is a mix of different vitamins and minerals, usually taken as a tablet. Some multivitamins are designed especially for pregnant women and will cover most of your vitamin needs.

Formulations vary, so check the label to make sure you will be getting what you need.

But multivitamins are not a substitute for a balanced diet. It's important to eat healthily even if you're taking prenatal multivitamins.

If you're pregnant, only take multivitamins that are designed for use in pregnancy.

What about other vitamins?

Your body only needs a small amount of each nutrient, and higher amounts are not necessarily better. In fact, consuming more than you need can sometimes cause harm.

For example, high doses of some vitamins can be dangerous:

• vitamin A
• vitamin C
• vitamin E

It's best not to take these vitamins as supplements during pregnancy.

Vitamin A

The best way to get enough vitamin A in pregnancy is from foods such as:

• meat
• fish
• leafy vegetables
• dairy products

Be careful not to take too much vitamin A in supplements. This may increase the risk of birth defects in pregnancy. Supplements usually provide vitamin A as retinyl esters, which are converted to retinol.

It's also best to avoid foods that may be very high in vitamin A, including liver and pâté.

Vitamin C

Vitamin C is found in a wide variety of fruits and vegetables. A balanced diet can give you all the vitamin C you need.

Enough vitamin C helps improve the absorption of iron from your diet.

Are there other dietary supplements I might need?

Your midwife or doctor might suggest you take a supplement for other reasons.

They may suggest:

• vitamin B12 — if you follow a vegetarian or vegan diet
• iron — if you have iron-deficiency anaemia
• calcium — if you're at risk of hypertension (high blood pressure)
• omega-3 fatty acids — if you're low in omega-3

Vitamin B12 is important since it supports the development of your baby's nervous system.

Omega-3 supplements during pregnancy may lower your risk of premature birth.

What should I do before starting a dietary supplement?

Because vitamins and dietary supplements are classed as low-risk medicines, they are not regulated as much as other medicines.

Vitamins and supplements can have side effects. Just as you should check with your doctor before taking any medicines while pregnant, it's best to do the same with supplements.

Resources and support

For more information about vitamins and supplements during your pregnancy:

• check the Australian Dietary Guidelines for more advice
• talk to your pharmacist, doctor, midwife or dietitian
• call 1300 MEDICINE on 1300 633 424 for advice about complementary medicines, Monday to Friday, 9am to 5pm AEST