Researchers have slammed the recommendation by a UK Department of Health committee that all flour should be fortified with folic acid, according to an article in the British Medical Journal (Volume 323, p 1198).

The recommendation is intended to reduce the level of neural tube defects in new born babies, caused by a lack of folic acid in pregnant women's diets, but child health experts Brian Wharton and Ian Booth warn that the policy requires careful consideration before it is implemented.

A similar policy in the US pre-empted a 19% reduction in the prevalence of neural tube defects. During the 1980s, however, a programme designe to heighten awareness of the importance of folic acid resulted in more than double the reduction, say Wharton and Booth.

Furthermore, the experts warn that while the benefits or supplementation are clear, the possibility of harm is to date unknown. The trial evidence necessary to launch a drug on the market is not also needed to enforce mandatory and universal fortification, they point out, adding that while a field trial may not be easy to conduct, it is essential when dealing with the potential effects on about 50 million people.