Folate is found in foods such as green leafy vegetables, chick peas and lentils, and an overwhelming body of evidence links has linked folate deficiency in early pregnancy to increased risk of neural tube defects (NTD) - most commonly spina bifida and anencephaly - in infants.
This connection led to the 1998 introduction of public health measures in the US and Canada, where all grain products are fortified with folic acid - the synthetic, bioavailable form of folate - and increasing debate in the UK over whether to add the nutrient to flour.
The UK's Food Standards Agency's Scientific Advisory Committee on Nutrition has asked the board for more time before delivering its final report on the fortification question. A spokesperson for the FSA told NutraIngredients.com in May that the ongoing investigations relate to increasing folate intake over 1mg per day.
In July, Ireland's National Committee on Folic Acid Fortication today recommended that most white, brown and wholemeal breads sold in the country be fortified with 120 micrograms of folic acid per 100g of bread - a move which will require legislative change and minor modifications to the bread-making process.
Food Standards Australia New Zealand (FSANZ) has also embarked on the path towards fortification, last month calling for public comment on a proposal that would require all bread-making flour to be fortified with folic acid.
But, while preliminary evidence indicates that the measure is having an effect with a reported 15 to 50 per cent reduction in NTD incidence, the study, published in the October issue of Gut (2006;55:1461-1466. doi 10.1136/gut.2005.085480), indicates that colorectal cancer risk is also a factor, and people with low folate levels may actually have some protection.
In an accompanying editorial, Dr Y-I Kim of the University of Toronto calls mandatory folic acid fortification "probably the most important science drive intervention in nutrition and public health in decades".
But given that certain segments of the population may benefit less and may even experience adverse effects, he said that wavering over fortification "should not be construed as public health malpractice but should be regarded as public health prudence".
In Dr Kim's opinion, long term follow-up studies into the relation between folic acid supplementation and fortification and cancer risk are "urgently warranted".