When you're pregnant or trying to conceive, there's a lot of information to take on board - including what vitamins you need to keep you and your baby healthy.
We've spoken to the experts and checked the research to separate the myths from the facts when it comes to taking pregnancy supplements.
Read on to find out what you pregnancy vitamins you should or shouldn't be taking.
Researchers reporting in the Drug and Therapeutics Bulletin journal concluded that most pregnant women don't need a pregnancy-specific multivitamin.
They pointed out that much of the evidence behind the marketing claims for pre-natal multivitamins comes from studies carried out in low income countries where women are more likely to be malnourished or undernourished.
In developed countries like the UK, our diets are generally good enough to give us most of the nutrients we need (with a few exceptions, see below) to sustain a healthy pregnancy.
Supplements formulated for pregnancy are perfectly safe so it's just a case of whether you want to spend the money on extra nutrients you're likely to be getting from diet anyway.
Folic acid is needed to help prevent birth defects called 'neural tube defects', including spina bifida. Official guidance is that you should take 400 micrograms (mcg) every day from the moment you start trying for a baby until the end of your first trimester (12 weeks).
You'll need to take a supplement even if you eat foods containing the natural form of folic acid (folate), such as spinach, broccoli, granary bread, beans and pulses.
Vitamin D helps us absorb calcium and phosphate, which are essential for bone and muscle health, and although some foods like oily fish, eggs and fortified foods contain vitamin D, it's difficult to get the amount you need from food alone.
The official guidance is for pregnant and breastfeeding women to take a 10 microgram (mcg) supplement each day to give their baby enough vitamin D for the first months of life.
There are a couple of extra vitamins you might need but not everybody will - unlike folic acid and vitamin D - so consult your doctor if you're unsure.
When pregnant or trying to conceive, you shouldn't take supplements or multivitamins that contain vitamin A as in high doses can harm the development of an unborn baby's nervous system.
The says you should also avoid foods that have vitamin A added to them - they may say 'fortified with vitamin A' on the label. However, you can eat fruit and vegetables that are high in carotenoids such as beta carotene from foods like carrots, pumpkin and mango.
Although multivitamins may contain key ingredients that pregnant women need - namely, folic acid and vitamin D - they might also contain ingredients that are aren't safe during pregnancy.
For example, Boots A-Z tablets contain 23 essential vitamins and minerals but they also contain vitamin A.
NICE, the National Institute for Clinical Health Excellence, says women who are pregnant or trying to conceive shouldn't take vitamin A supplements, except on their doctor's advice.
Not only can standard multivitamins contain vitamin A, the dosage levels of vitamin D and folic acid may not be high enough for conception and pregnancy.
For example, Centrum Advance is a standard one-a-day vitamin but it only contains 200mcg of folic acid and 5mcg of vitamin D per daily dose, both of which are insufficient for pregnant women.
The British Nutrition Foundation says that long-chain omega-3 fatty acids - especially DHA (docosahexaenoic acid) found in oily fish - are important for brain and eye development in your baby.
Shefalee Loth, Which? Nutritionist, says: 'If you are eating one portion of oily fish a week you will be getting what you need from this, but if you aren't then you might want to consider a fish oil supplement.'
Make sure it's suitable for pregnant women, as some fish oil supplements (such as cod liver oil) contain a high amount of vitamin A, which you should avoid during pregnancy.
Instead, choose ones that are extracted from the tissue of deep sea cold water fish and suitable for conception and pregnancy. Consult your pharmacist if you're unsure.
It may be tempting to think that because they're 'natural' they must be OK for you and your developing baby.
However, Claire Anderson, president of the Royal Pharmaceutical Society, says: 'Not all natural remedies or complementary therapies are safe in pregnancy. Some products used may not be of a high quality and may contain other substances that could be harmful.'
She says that if you want to take herbal supplements prior to, or during, pregnancy, ask a health professional such as a pharmacist or GP for advice as herbal remedies can be potent and have potential side effects.
As for the safety of herbal and green teas (which contain caffeine), it's best to limit how much you drink to no more than a couple of cups a day.
We've taken a look at what's available for mums-to-be when it comes to supplements and found that prices vary a great deal.
Although experts say you don't need a pregnancy multivitamin, if you were to buy one you could find yourself paying as as much as 99p per day or as little as 6p per day.
Below are the prices for a selection of pregnancy multivitamins, including one-a-day, two-a-day, and oral spray and gummies, presented in order of descending cost.
|Supplement name||Cost per packet||Cost per day|
|£29.99 for 60 tablets (30 day supply)||99p|
|£19.99 for 60 capsules (30 day supply)||66p|
|£14.95 for 25ml (32 day supply)||47p|
|£14 for 60 gummies (30 day supply)||46p|
|£5 for 28 tablets (28 day supply)||18p|
|£4.50 for 30 tablets (30 day supply)||15p|
|£9.50 for 90 tablets (90 day supply)||11p|
A cheaper supplement that contains these alone is sufficient (unless you're advised otherwise by your doctor) and more cost-effective.
For example is £2.50 for 180 tablets (1.4p per day) and is £3 for 90 tablets (3.3p per day), which means you get these essential pregnancy nutrients for 4.7p per day - more than 20 times cheaper than the most expensive pregnancy multivitamin we looked at.
BetterYou Pregnancy Daily Oral Spray works out at 47p per day.
Look out for deals at pharmacies or health shops such as three for the price of two, as this can bring the price down.
If you're in any doubt about taking supplements during your pregnancy or while you are breastfeeding, speak to your GP or another health professional such as a pharmacist.