To provide a basis for making recommendations on the potential to improve use of folic acid supplements in the UK, particularly among low-income and young women.

Systematic reviews of relevant research from 1989 to May 2006 in Europe, the USA, Canada, Australia and New Zealand.

Twenty-six systematic reviews and/or meta-analyses were identified from the wider public health literature, and eighteen studies on the effectiveness of preconception interventions were included. Ninety studies were identified which were directly relevant to folic acid supplement intake. There were factors that are particularly associated with lower rates of use of folic acid supplements. One of the most important of these is the link with unintended pregnancy, followed by age, socio-economic and ethnic group. Integrated campaigns can increase the use of folic acid supplements to some extent. Research trials indicated that: (i) printed resources and the mass media used in isolation are not effective in the longer term; and (ii) health-care-based initiatives can be effective and are more likely to be successful if they include making supplements easily available.

Campaigns and interventions have the potential to exacerbate socio-economic inequalities in folic acid use. One way of addressing this is to include elements that specifically target vulnerable women. To achieve and maintain an effect, they need to be based on good health promotion practice and to be sustained over a long period. However, even high-quality campaigns that increase use result in under half of women in the target group taking supplements.