Folic Acid - Why it is an important supplement to take when trying to conceive and during pregnancy

Should you take Folic Acid? When you’re trying to conceive knowing just which supplements you should be taking can be difficult. There are so many you could take, but many of these don’t have the evidence base behind them, and it’s so important to take the right supplements for you. However there is a supplement to take that is crucial and has all the evidence to support it’s use and this is folic acid. This blog was written by Nitin Makadia (BSc MRPhamS) who is the Medical Writer for the lovely people at Dr Fertility and first published on their blog.

Whether you are thinking about your journey to start a family or have been trying to conceive for some time, an important nutrient you might have come across is folic acid. The UK Department of Health recommends that all women who are planning a pregnancy should be taking a folic acid supplement in addition to a varied and nutritionally balanced diet (1). This is because, unlike most other vitamins, it is very difficult to get the recommended amount of folic acid for pregnancy from diet alone (1).

Despite this, researchers found that, amongst nearly 500,000 women who were questioned, fewer than one in three took this supplement before becoming pregnant (2).

What is folic acid and why is it important?

Folic acid, also known as vitamin B9, is found in foods such as leafy green vegetables, brown rice, granary bread and also in cereals which are fortified with the supplement (1). The Government is also considering fortifying flour with folic acid because it is so important (3). At this point it would be useful to mention that you may see folic acid also being called folate. Folate is another form of folic acid that is naturally found in food, whereas folic acid is the man-made form found in most supplements. Your body converts folic acid into folate before it can be used. For now, it’s easier to think about them as being the same thing.

Folic acid has a number of important roles in the body, such as helping you to make healthy red blood cells (5). For now we will focus on its role in the early part of pregnancy. It also helps your baby’s brain and spinal cord to develop properly and help prevent neural tube defects, such as spina bifida. In the UK, around 1000 pregnancies are affected by neural tube defects each year (3).

When and how much should you take?

Most women planning a pregnancy should take a daily supplement containing 400 micrograms of folic acid on top of what they should already be getting from a healthy balanced diet.
You should ideally start to taking the supplement 2-3 months before you are planning to start a family, so that you have the right level in your body when you conceive. You should then carry on taking it for at least 12 weeks into your pregnancy(1) to maintain the right amount for those crucial first few weeks when your baby’s brain and spinal cord are developing, reducing the risk of your baby developing a neural tube defect by 70% (4).

Some women may have a higher risk of their pregnancy being affected by a neural tube defect. This might be if you or your partner have any history of neural tube defects in your families, or in previous pregnancies(1). There is also an increased risk if you have diabetes, are taking anti-epilepsy medicines or in women who are obese with a body mass index (BMI) of over 30(7). If this is the case, you may need to take a higher daily dose of 5 milligrams, which your GP can prescribe if it’s appropriate for you (1). If you have any medical conditions or allergies, it’s always best to check with your doctor before starting to take the supplement just in case it’s not suitable for you (5).

What if you haven’t been taking the supplement before you become pregnant?

Firstly, don’t panic! If you are already taking a supplement designed specifically for fertility or for pregnancy, just check the ingredients. Chances are it may already contain 400 micrograms of folic acid, or folate, per daily dose. Not all supplements do, so it’s best to check and, if it doesn’t already contain these, then start taking some as soon as you can, as long as it’s not something you need to check with your GP first, as mentioned above.

If you are now more than 12 weeks pregnant and have not been taking a folic acid supplement, it’s important to know that the chances of your baby developing a neural tube defect are still very small. For example, spina bifida is found in only 6 out of every 10,000 babies (6). Talk to you GP or midwife about any concerns you have so that they can keep a close watch on your baby’s health as part of your routine antenatal care.

So, the takeaway messages are, as long as there are no other health concerns:

  • Eat a healthy, nutritionally balanced diet every day which is rich in folic acid containing foods, such as green leafy vegetables, brown rice, granary bread and cereals
  • Make sure you are taking the recommended daily dose, either on its own or contained within another fertility supplement. If you take a multivitamin supplement, do make sure it doesn’t contain vitamin A (also known as retinol), which is harmful in pregnancy if you take too much.8 It’s important to do this in addition to eating foods rich in folic acid
  • Get into a routine of taking your supplement every day, perhaps in the morning with breakfast, so that you don’t forget


  1. Why do I need folic acid in pregnancy? [Online content accessed 14.04.20]
  2. Bestwick JP, Huttly WJ, Morris JK, Wald NJ. Prevention of neural tube defects: a cross-sectional study of the uptake of folic acid supplementation in nearly half a million women. PLoS One. 2014;9(2):e89354. doi: 10.1371/journal.pone.0089354
  3. Proposal to add folic acid to flour: consultation document [Online content accessed 15.04.20]
  4. Beaudin A.E., Stover P.J. Insights into metabolic mechanisms underlying folate-responsive neural tube defects: a minireview. 2009 Apr;85(4):274-84. doi: 10.1002/bdra.20553.
  5. NHS UK: Folic acid [Online content accessed 14.04.20]
  6. PHE Screening: New spina bifida and anencephaly information leaflets for parents published [Online content accessed 15.04.20]
  7. NHS UK: Conditions/Spinda bifida [Online content accessed 16.04.20}
  8. NHS UK: Vitamins, supplements and nutrition in pregnancy [Online content accessed 16.04.20]