Taking vitamins during pregnancy linked with reduced risk of autism

A new study, published today in JAMA Psychiatry[1], has found that women who took multivitamins and folic acid either before or during pregnancy were significantly less likely to have a child who went on to develop autism spectrum disorder.


The study followed 45,300 Israeli children (of which around half were girls) born in 2003-2007 and checked for a diagnosis of autism up until January 2015. During this time, 572 (1.3%) children received a diagnosis of autism.

Commenting on the study, dietitian, Dr Carrie Ruxton from the Health and Food Supplements Information Service said: “The results showed a 61% reduced risk of autism when mothers had taken either a multivitamin and/or folic acid supplement prior to becoming pregnant. It was also found that mothers who took these vitamin supplements during pregnancy were 73% less likely to have a child who went on to be diagnosed as autistic.

“While this is an observational study and we need to be cautious, it is an important finding which contributes to our body of knowledge on factors linked with autism.

“Around 75% of women of childbearing age in the UK have an inadequate folate status putting their children at risk of neural tube disorders, such as spina bifida[2]. Only a quarter of women take the recommended folic acid supplements before conception and in the first trimester of pregnancy[3]. It is possible, given these new findings, that a lack of key nutrients may also be an issue for autism risk”.

“According to autism charities, over 695,000 people in the UK may be autistic, with a prevalence rate of 1.1% in children[4].  Taking a daily multivitamin is a useful way of ensuring that women have the nutrients they require. If planning a pregnancy, a daily folic acid supplement of 400 micrograms should be added to this”.



HSIS (the Health and Food Supplements Information Service) is a communication service providing accurate and balanced information on vitamins, minerals and other food supplements to the media and to health professionals working in the field of diet and nutrition.

[1] Levin, SZ et al Are Vitamin Supplements Used Before or During Pregnancy Associated with Risk of Autism Spectrum Disorder?http://jamanetwork.com/journals/jamapsychiatry/fullarticle/10.1001/jamapsychiatry.2017.4050

[2] Bates B et al. (2015) NDNS Supplementary report: blood folate results for the UK as a whole, Scotland, Northern Ireland (years 1 to 4 combined) and Wales (years 2 to 5 combined). London.

[3] SACN (2017) Folic acid: updated recommendations www.gov.uk/government/publications/folic-acid-updated-sacn-recommendations

[4] http://www.autism.org.uk/about/what-is/myths-facts-stats.aspx