Supplements for would-be parents

For women

Folic acid: If you’re thinking about having a baby you should start taking a folic acid (vitamin B9) supplement of 400mcg per day – preferably for three months before you try to conceive. It’s very important to the healthy development of a foetus and can reduce the risk of defects to the brain and spinal cord known as neural tube defects, such as spina bifida.

Calcium: The recommended daily intake of calcium for pregnant women is 1000mg.

It’s vital for your and your baby’s healthy bones and teeth, circulatory, muscular and nervous systems. If you are trying to conceive you just need to ensure you are keeping up your normal levels of calcium as part of a healthy balanced diet. If you're lactose intolerant and use soy milk, then make sure that your brand of soy milk is fortified with calcium.

If you're worried that you're not getting enough calcium, for instance if you don't eat dairy products, then you can take a calcium supplement. Specific antenatal vitamin tablets will include calcium, but may contain only a third of the recommended daily amount, so make sure you check.

Iron: Iron is essential for making the haemoglobin that carries oxygen in red blood cells to all parts of the body. During pregnancy your body needs to increase its blood supply by 50%, so you need plenty of iron to make all the extra haemoglobin for new red blood cells. If you aren't getting enough iron then you may suffer from anaemia.

Iron tablets can cause, or aggravate, digestive problems like constipation, so unless you are actually anaemic the best way to get your iron is through natural sources.

Magnesium: Important for creating and renewing bone, protein and fatty acids, magnesium also relaxes muscles. Magnesium helps your body build and repair all the body tissue it needs as you develop and support your growing baby.

The most serious possible consequences of a magnesium deficiency are an increased risk of both pre-eclampsia and premature labour. The 'right amount' of magnesium during pregnancy is around 350mg daily. If you do take a magnesium supplement then be aware that it can inhibit the absorption of iron, so shouldn't be taken within two hours of an iron supplement.

For Men

Zinc: This helps to boost testosterone and raise sperm counts. This is a popular supplement for men before conception and you’ll find-small dose pills easily available (you don't need more than 50mg a day) or you can make sure you keep up meat, seafood, pulses and eggs in your diet.

Vitamin C: Not only is vitamin C useful in general health, valuable to help the body absorb iron and as an anti-oxidant, it helps keep sperm levels up and gets them swimming! Make sure your diet is rich in vitamin C from citrus fruits, berries, potatoes and green vegetables.

Vitamin E: This can be derived from vegetables, vegetable oils, fish and poultry. Again, it aids sperm 'motility' (sperm’s 'get up and go') and can help with fertilisation.

Folic acid: This is a popular nutrient for women before conception and through to the first half of pregnancy, but is also valuable for men as it has been found to boost sperm count.

Other useful nutrients: Try popping a few brazil nuts each day – they're rich in selenium, which is great for sperm function.