Should I take folic acid?

Taking folic acid in pregnancy is vital, but newspaper reports have linked it to asthma in children. Mary Salmon finds out the truth behind the headlines

Yes
Folic acid is a B vitamin which is essential for the health of a developing baby, reducing the risk of neural tube defects such as spina bifida.
While the vitamin occurs naturally as folate in foods such as beans, lentils, brown rice and leafy green vegetables like spinach, a lot of people don’t get enough of this nutrient in their diet.
Folic acid is sometimes added to foods by manufacturers to improve the nutritional quality of certain products, such as bread and breakfast cereals. ‘As many pregnant women require extra folate and aren’t getting enough from their diet, supplementing is necessary,’ says Dr Sian Astley, a research scientist at the Institute of Food Research. ‘The research showing that taking folic acid pre-conception and in early pregnancy is watertight – the vitamin is important for the correct development of the spine and brain of the foetus very early in pregnancy.’
Current government advice in the UK is that all women thinking of having a baby should take 400 micrograms of folic acid every day from the time they stop using contraception until the 12th week of pregnancy.
While a recent Australian study found that folic acid may cause asthma in the children of women who take it in pregnancy, this was only in those who took it in late pregnancy (between 30 and 34 weeks). And experts say the study isn’t reliable. ‘The research was based on a postal questionnaire so it may not be dependable,’ says Dr Roger Bayston, President of the Society for Research into Hydrocephalus and Spina Bifida. ‘This means it isn’t possible to pinpoint any problems to folic acid.’
He points out that while asthma is a treatable condition, spina bifida, which causes everything from stillbirths to severe paralysis, is extremely serious. ‘The benefits of taking folic acid in early pregnancy outweigh any potential risks.’

No
Taking folic acid in early pregnancy is beneficial to an unborn child, but taking it after 30 weeks of pregnancy might not be a good idea. As well as the recent study published in late 2009 from the University of Adelaide in Australia, which showed that folic acid taken in late pregnancy may increase the incidence of asthma in children by 30 per cent, another study carried out in Norway found a similar effect.
The problem appears to be caused by folic acid being digested differently to folate. ‘Folate is broken down by the stomach, whereas folic acid, which is broken down by the liver, floats around in the bloodstream until the liver deals with it,’ explains Dr Astley.
It is thought that when folic acid is floating freely in the blood it has the potential to cause allergy-encouraging reactions in developing babies. ‘It is a complex process and another study done in 2008 also supports the theory,’ adds Dr Bayston.
The evidence against folic acid isn’t clear cut though. ‘Other studies show folic acid might help prevent cancer,’ says Dr Bayston. Thankfully, there is no controversy about folic acid when it is obtained as folate from food.
‘It is a fast moving area of research and isn’t black and white,’ adds Dr Astley. ‘The jury is still out.’

Healthy Verdict
The study which linked asthma to folic acid only referred to late pregnancy. Women are still advised to take folic acid before conception up until the 12th week of pregnancy. The research proving the benefits of folic acid in preventing neural tube defects is strong and we advise following government guidelines to protect your developing baby.