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Healthy eating and vitamin supplements in pregnancy patient information leaflet

This information is for you if you want to know more about eating healthily in pregnancy.

It also gives you advice on using vitamin supplements before and during pregnancy.

Healthy eating

Keeping healthy when you are having a baby depends on both the amount and the type of food you eat before you become pregnant and during your pregnancy. Simply being a correct weight for your height does not necessarily mean that you are eating healthily. Some foods are best avoided if you are planning to become pregnant or if you are already pregnant, as they may contain substances that could affect your unborn baby’s development.

To eat healthily, you should aim to do the following.

  • Base your meals on starchy foods such as potatoes, bread, rice and pasta, choosing wholegrain if possible. These foods are satisfying without containing too many calories.
  • Eat at least five portions of different fruit and vegetables every day rather than foods that are higher in fat and calories. Potatoes do not count towards your five-a-day target, and a portion of pure fruit juice only counts as one of your five-a-day, no matter how much you drink.
  • Eat a low-fat diet and don’t increase the number of calories you eat. Eat as little fried food as possible and avoid drinks that are high in added sugars, and other foods such as sweets, cakes and biscuits that have a high fat or sugar content.
  • Instead, eat fibre-rich foods such as oats, beans, lentils, grains and seeds, as well as wholegrain bread, brown rice and wholemeal pasta.
  • Eat some protein every day; choose lean meat, and try to eat two portions of fish a week. Lentils, beans and tofu are also a good source of protein.
  • Eat dairy foods for calcium but choose low-fat varieties such as skimmed milk or low-fat yogurt.
  • Watch the portion size of your meals and snacks and note how often you eat. Do not ‘eat for two’.
  • Always eat breakfast.
  • Limit your caffeine intake to 200 milligrams (mg) per day, for example two mugs of instant coffee. Be aware that other drinks such as tea and energy drinks also contain caffeine.

Most women do not need any extra calories during the first six months of pregnancy. It is only in the last 12 weeks that they need to eat a little more, and then only an extra 200 calories a day, which is roughly the same as two slices of bread.

You can find out your healthy weight from your BMI (body mass index). This is a measure of your weight in relation to your height. Your healthcare team can work it out for you. A healthy BMI is above 18.5 but below 25. Being overweight carries risks for you and your baby (see the RCOG patient information Being overweight in pregnancy and after birth).

The more overweight you are, the greater the risks. Being underweight increases the risk of your baby not growing as well as he or she should.

Trying to lose weight by dieting during pregnancy is not recommended as it may harm the health of your unborn baby. If you are concerned about your weight, your midwife can advise you and may refer you to a dietician.

In general, eating fish is a healthy option during pregnancy, but the current advice from the Department of Health is to eat no more than two portions of oily fish, such as mackerel or salmon, a week. This is because too much of a substance found in oily fish (mercury) can be harmful to an unborn baby’s development.

Also, pregnant women should not eat more than two fresh tuna steaks or four medium-sized cans of tuna a week, and should avoid eating shark, swordfish or marlin.

Liver can contain high levels of vitamin A, which in high doses can harm the development of an unborn baby’s nervous system. It is rare for women in developed countries like the UK to be deficient in vitamin A so you should avoid eating foods such as liver and liver products like pâté.

You can eat peanuts or foods containing peanuts (such as peanut butter) while pregnant or breastfeeding. Eating peanuts does not appear to affect your baby’s chances of developing a peanut allergy. Don’t eat them if you’re allergic to them.

You can pick up some infections, such as listeria, salmonella or toxoplasmosis, from contaminated food. These can harm your unborn baby.

To reduce your risk of getting listeriosis:

  • drink only pasteurised or UHT milk
  • avoid eating ripened soft cheese such as Camembert, Brie or blue-veined cheese; however, hard cheese varieties such as Cheddar, cottage cheese and processed cheese are safe
  • avoid eating pâté
  • avoid eating undercooked food; make sure that ready-prepared meals are cooked as per instructions, paying particular attention to making sure that they are piping hot when reheating.

To reduce your risk of getting salmonella:

  • avoid eating raw or partially cooked eggs or food that may contain them, such as some types of mayonnaise or mousses; check the packaging of the food to see what is in it.
  • avoid eating raw or partially cooked meat, especially poultry and shellfish.

To reduce your risk of getting toxoplasmosis:

  • always wash your hands before and after handling food
  • wash all fruit and vegetables, including ready-prepared salads
  • cook raw meats and ready-prepared chilled meats thoroughly
  • wear gloves and wash your hands thoroughly after gardening or handling soil
  • avoid contact with cat faeces (in cat litter or in soil) – or, if you must handle it, wear rubber gloves.

Vitamins are needed for growth and development. There are 13 important vitamins: vitamins A, C, D, E and K and the vitamin B series. Apart from vitamin D, which we get from sunlight, most vitamins come from our diet. In the UK, it is quite common for people to be low in vitamin D and folic acid (vitamin B9). These vitamins are important in pregnancy and you can boost your levels by taking a vitamin supplement. Supplements of other vitamins are not usually advised since they may actually be harmful in pregnancy. The various vitamins and whether they are recommended in pregnancy are detailed below.

Vitamins that are recommended

Folic acid

Folic acid is one of the B vitamins and helps to reduce the risk of your baby having spina bifida. Taking extra folic acid may also reduce the risk of heart or limb defects and some childhood brain tumours. The recommended daily dose is 400 micrograms (µg). Ideally, you should start taking extra folic acid before you conceive and continue to take it until you reach your 13th week of pregnancy. If you did not take folic acid before you became pregnant, start taking it as soon as you realise you are expecting a baby.

Some women take a higher dose of folic acid. Why?

If your risk of having a baby with spina bifida is higher than normal, you will be advised to take a daily dose of 5 milligrams (mg) of folic acid. This is higher than usual and it will need to be prescribed by a doctor. You may be advised to take an increased dose if:

  • you have had a previous pregnancy affected by spina bifida
  • you or your partner have spina bifida
  • you are taking certain medications for epilepsy
  • you have coeliac disease or diabetes
  • your BMI is 30 or more
  • you have sickle-cell anaemia or thalassaemia; the higher dose of folic acid will also help to prevent and treat anaemia if you are in this situation.

Vitamin D

All pregnant women are advised to take a daily dose of 10 micrograms (µg) of vitamin D when pregnant and breastfeeding. This is because it is common in the UK for people to have low levels of vitamin D. Taking supplements can improve your baby’s growth during his or her first year of life, and can reduce their risk of developing rickets.

You are at particular risk of having low levels of vitamin D if:

  • your family origin is South Asian, African, Caribbean or Middle Eastern
  • your BMI is 30 or more
  • you stay indoors a lot
  • you usually cover your skin when you go outdoors or usually use sun-protection cream
  • your diet is low in vitamin D-rich foods such as eggs, meat, vitamin D-fortified margarine or breakfast cereal.

If you are in one of these situations, you may be may be advised to take a higher daily dose of vitamin D.

When may I need extra vitamin K?

Vitamin K is needed for our blood to clot properly. Newborn babies have low levels of vitamin K, which puts them at risk of bleeding . To prevent this, you will be offered vitamin K for your baby after birth.

You do not need to take vitamin K supplements yourself during pregnancy unless it is thought that your baby is at particular risk of bleeding. This could be because you are taking certain medicines for epilepsy or if you have liver disease.

When may I need extra vitamin C?

Although routine supplements of vitamin C are not specifically recommended when you are pregnant, this vitamin helps iron to be absorbed. This may be of benefit during pregnancy, at a time when women are at risk of becoming anaemic.

Vitamins that are not recommended

There are many multivitamin tablets for use in pregnancy that contain a small amount of lots of vitamins. These are safe to take, but avoid taking large doses of the following vitamins unless a doctor prescribes them for a particular reason.

Vitamin A

Too much vitamin A can harm the development of your unborn baby’s nervous system. During pregnancy, avoid any supplements that contain more than 700 micrograms (µg) of vitamin A and don’t eat foods such as liver, liver products (pâté) or fish liver oils that may contain this vitamin in high levels.

Vitamin E

There is currently no evidence to recommend additional vitamin E during pregnancy.

Vitamin B supplements (other than folic acid)

You do not need any other vitamin B supplements in pregnancy. Sometimes, pyridoxine (vitamin B6) is prescribed to help you feel less sick early in your pregnancy although it will not stop you from being sick.

What about extra iron?

Most women do not need to take extra iron during pregnancy. Taking routine iron supplements will not necessarily benefit your health and may cause you unpleasant side effects such as heartburn, constipation or diarrhoea. Your midwife will check your blood at your booking appointment and at 28 weeks of pregnancy. You will only be advised to take iron if you are found to be anaemic or are at increased risk of becoming anaemic in pregnancy, for example if you are carrying twins.

If you are on certain benefits and/or are under the age of 18 years, help may be available to provide you with free supplements.

You can buy folic acid or pregnancy multivitamins from any pharmacy or supermarket. There is no evidence that expensive brands are any better than cheaper ones.

The following website can give you information about healthy eating before and during pregnancy and while breastfeeding:

NHS Choices – Your Pregnancy and Baby Guidewww.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy- and-baby-care.aspx#close.

Shared Decision Making

If you are asked to make a choice, you may have lots of questions that you want to ask. You may also want to talk over your options with your family or friends. It can help to write a list of the questions you want answered and take it to your appointment.

Ask 3 Questions

To begin with, try to make sure you get the answers to 3 key questions, if you are asked to make a choice about your healthcare:

  1. What are my options?
  2. What are the pros and cons of each option for me?
  3. How do I get support to help me make a decision that is right for me?

*Ask 3 Questions is based on Shepherd et al. Three questions that patients can ask to improve the quality of information physicians give about treatment options: A cross-over trial. Patient Education and Counselling, 2011;84:379-85 

Sources and acknowledgements

This information has been developed by the RCOG Patient Information Committee. It is based on information from the NHS Choices website above and the RCOG scientific impact paper Nutrition in Pregnancy (September 2010), which contains a full list of the sources of evidence we have used.

This information has been reviewed before publication by women attending clinics in London, Sheffield and Kirkcaldy.

A glossary of all medical terms is available on the RCOG website here.