Should I be taking vitamin supplements in pregnancy and which ones?

7 things to know:

1. Folic acid is important to take for 3 months before pregnancy and for at least the first 12 weeks as it reduces the risk of spina bifida. You can continue it all pregnancy although if your diet is healthy, stopping at 12 weeks is fine.
2. If you got pregnant unexpectedly, start taking this as soon as you can.
3. You should take 400mcg per day, or if you are high risk 5mg per day (eg overweight). 
4. If you forget to take it one day, just take it as soon as you remember and carry on
5. The only other supplement you will need to consider is vitamin D in the winter months between October and March. Take this all pregnancy and whilst breast feeding. Take at least 10 mcg/400IU units a day.
6. Multivitamins are not usually necessary but can be a convenient way of taking both vitamin D and folic acid.

Is it necessary to take multivitamins during pregnancy?

There are some supplements which are important during pregnancy but for most people who eat a healthy diet, it is not necessary to regularly take vitamin supplements.

Folic Acid

The most important one is folic acid. This is really important for 3 months before you conceive and for the first 12 weeks. This is because it is known to reduce the risks of the baby developing spina bifida, which is a congenital abnormality of the baby’s spine.  

The dose of folic acid is also important. For most women, 400mcg is adequate, which is the dose you can buy in supermarkets, either on its own or in a multivitamin like Pregnacare.

If you are higher risk for having a baby with spina bifida, then 5mg is recommended. Women who are at higher risk are those with a higher body mass index over 30kg/m² and those who have had a baby before affected by spina bifida. The higher dose has to be prescribed by a doctor.

You may also have heard of an alternative, known as methylfolate (same dose 400mcg). This is a form of folic acid that can be used directly by the body. There are some people who have genetic changes which means that they cannot change the usual form of folic acid into the active version for the body to use. This means they may not get the same benefit from taking folic acid. Although you can be tested for these genes, it is expensive.

Taking methylfolate gets round this problem as the body can use it directly. At present, this is not recommended in the UK and methylfolate is not licensed for use in pregnancy. Also, there are no studies which have looked at whether it is effective in reducing the risk of spina bifida. However, it’s use is logical and some doctors in the UK and overseas recommend it in preference to folic acid. 

What if I didn’t take folic acid before conception?

If you conceive unexpectedly and did not take folic acid for the 3 months before you conceive, do not panic. Like many things, folic acid supplements reduce the risk rather that prevent altogether and not taking it does not mean disaster. Start taking folic acid as soon as you can. The vast majority of women who do not take folic acid do not have a problem during the pregnancy. Similarly, folic acid does not stop spina bifida happening, it just reduces the risk. You do not need to keep taking folic acid after 12 weeks, but it will not cause harm if you continue it. Some people’s diet is low in folic acid so it is no bad thing to continue. 

Vitamin D

The only other vital vitamin to consider in pregnancy is vitamin D. Vitamin D is vital to your baby’s development. The baby needs it to develop healthy bones and deficiency can cause a disorder called rickets where the baby’s bones become very soft. There have been cases of rickets in the UK so we need to take this seriously.  

During the winter months, many women in the UK become deficient because we do not get much daylight and sunlight and people tend to stay outdoors. This is because vitamin D forms due to exposure of the skin to sunlight and it is actually quite hard to get enough during the winter from the diet.

It is found in fatty fish (like salmon, mackerel, and sardines), egg yolks, red meat, liver, and mushrooms, and some manufactured foods will add it during the manufacturing process.

It is recommended that all pregnant women take vitamin D supplements during winter months (October – March), at a dose of 400 units or 10 micrograms. You might want to take this all year round if you do not expose your skin to daylight very much, or wear very high protection sunblock all the time in the sun.  

You should carry this on if you are breast feeding, and you will also be advised to give your baby vitamin D supplements. 

In the UK, the NHS does not offer screening for vitamin D deficiency to pregnant women. However, there may be some benefit for some women, especially if you have dark skin but you would probably have to access this privately. If you are vitamin D deficient in pregnancy, it is important to replace this deficiency, but this would need higher doses depending on your level of vitamin D.

Which type of multivitamin may be helpful to me?

It is not necessary to take a multivitamin during pregnancy, but some women choose to. It can be easier, for example, to take a multivitamin which contains both folic acid and vitamin D every day than it is to take individual tablets. For the most part, there is likely to be little benefit to taking all the other components in a multivitamin if you are eating a healthy and balanced diet. However, the vitamins will likely do no harm. Most of the multivitamins do not contain enough iron to treat or prevent anaemia for example. If you do wish to taken a multivitamin, taking one which includes iodine may be helpful, as this is a nutrient that supports the thyroid gland to produce thyroid hormone and can occasionally be of benefit. Some countries around the world recommend iodine supplementation in pregnancy.