We breathed a sigh of relief at the Chief Medical Officer’s recent intervention to stall the Food Standards Agency’s (FSA’s) proposal to fortify bread with folic acid.

The move was triggered by a review in the British Journal of Nutrition. This found it was wrong of the FSA to assume folic acid would behave the same as the natural form of the B vitamin, folate.

It turns out that unmetabolised folic acid appears in the body after eating just one slice of fortified bread and then accumulates as more is eaten. This is a huge concern, as many negative effects are associated with unmetabolised folic acid: cancer, mental decline in the elderly, more multiple births among women having fertility treatment (which have higher health risks), and reduced success of anti-folate drug treatment.

These surely outweigh the tiny predicted reduction in neural tube defects (NTD) - 22-36 fewer NTD births each year, plus up to 110 fewer terminations - that was the sole objective of fortification.

It is worrying how the FSA’s ’science-based’ proposal was actually based on assumptions. This seems to be a repeat of the situation with other vitamins, where natural and artificial nutrient sources were wrongly assumed to have the same effects.