Ideally you should start taking 500 micrograms (mcg) of folate a day in tablet form one month before you start trying to get pregnant. If you discover you’re pregnant and haven’t been taking folate, don’t panic but do start taking it as soon as you can and continue to do so through your first trimester. Folate is essential for the development of the brain and spinal cord, and can prevent the risk of neural tube defects such as spina bifida by up to 70 percent.

In later stages of pregnancy as the baby’s nutritional needs take priority over the mother’s, it may be necessary to also take calcium and iron supplements. In the first couple of months, generally iron deficiency is not an issue because your body has stopped menstruating. However as the baby grows and its blood supply increases, anemia can set in. If you do require an iron supplement, look for one that also includes Vitamin C to aid iron absorption, and ask your health practitioner to recommend one that doesn’t cause constipation.

Similarly, the third trimester is the critical time for strengthening baby’s bones and therefore if you’re finding it hard to meet your daily requirements of calcium, a supplement may be necessary. You may also wish to continue to take calcium until you’ve finished breastfeeding.

A specialised prenatal supplement is likely to be necessary if you:

* are a vegetarian or vegan

* are lactose-intolerant or have other food intolerances

* are a teenager with an inadequate food intake

* smoke or take non-prescription drugs

* are expecting twins or higher multiples

* are obese and need to prevent further weight gain

* have diabetes, gestational diabetes or anemia,

* have a history of low birth weight babies.

If any of these conditions apply to you, speak to your health professional about what kind of supplement is best for you. If you decide to take a supplement... If you don’t have any health conditions but are finding it difficult to follow a balanced diet, then you may decide to take a multivitamin complex. In this case, choose a pregnancy / breastfeeding formula rather than just a general women's multivitamin.

Generally, you'll find pregnancy supplements include higher levels of folate and iron, but also lower levels of potentially harmful vitamins such as Vitamin A.