Update Report on Folic Acid and the Prevention of Birth Defects in Ireland Published by Food Safety Authority of Ireland

The Food Safety Authority of Ireland has published an Update Report on Folic Acid and the Prevention of Birth Defects in Ireland. The Executive Summary is below. The full report may be found here: http://connection.teratology.org/p/do/sd/sid=730&fid=2206&req=direct

Executive Summary

Neural tube defects (NTDs), including spina bifida, anencephaly and related defects, are the most common major malformations of the central nervous system. There was a large decrease in incidence rate of NTDs in Ireland from the early 1980s (about 3.5 per 1,000 births) to the mid-1990s; however, the rate has remained relatively stable since then at about 1 per 1,000 births (about 80 cases per annum), similar to the UK. Recent studies suggest that the incidence of pregnancies in Ireland affected by NTDs may have increased between 2005-6 and 2010-11.

About 70% of NTDs are preventable with folic acid, a form of the B-vitamin folate, if taken from before conception until about the fourth week of pregnancy. Since 1993, the policy in Ireland has been to provide advice to all women of childbearing age who are capable of becoming pregnant, whether planning to do so or not, to take 400 μg of folic acid daily as a supplement. To date, this has had limited effectiveness and the rate of NTDs in Ireland remains significantly higher than in countries with mandatory fortification such as the United States (about 0.6 per 1,000 births). This is because compliance by women of childbearing age in Ireland with the recommendation to take a daily supplement of folic acid is generally poor, similar to experiences in other European countries. Voluntary fortification of food with folic acid by manufacturers makes a significant contribution to reduction in risk of NTD-affected pregnancies in Ireland (about 11-14%). It is estimated that about 36% of women of childbearing age in Ireland have blood folate levels that are adequate for optimal protection against NTDs.

Mandatory fortification of food staples, such as flour or cereals, has proved effective in decreasing the prevalence of pregnancies affected by NTDs in over 80 countries that have implemented this approach, e.g. by 35% in the USA. The experience of mandatory fortification of foods with folic acid in the USA since 1996 has shown that there is no evidence for the occurrence of adverse health effects in any population group following introduction of fortification. This report shows that in Ireland mandatory fortification of bread or flour to provide about 150 μg of folic acid per day in women of childbearing age could reduce the prevalence of NTDs by approximately 30%. Provided voluntary fortification of foods was continued, the benefit for reduction in the risk of occurrence of NTD-affected pregnancies by these foods could be retained. Mandatory fortification of flour or bread with folic acid would require legislation. An implementation programme would be needed to address legislation, consumer acceptability and consumer choice, technical issues, cost, and trade implications.

While voluntary food fortification with folic acid does make a significant contribution to reduction in risk of NTDs in Ireland, the lower level and uneven distribution of intake of folic acid among women of childbearing age makes it less effective than mandatory fortification. There is potential to improve the effectiveness of voluntary fortification by providing guidance on voluntary fortification of selected foods with folic acid by manufacturers, e.g. for levels of fortification and the range of foods fortified, in conjunction with a voluntary labelling scheme.

As mandatory or voluntary fortification of food with folic acid would only provide women with a proportion of the recommended amount to prevent occurrence of NTDs, the current policy of providing advice to all women of childbearing age who are capable of becoming pregnant to take an additional 400 μg folic acid daily as a food supplement would need to be continued. Ongoing campaigns are required to promote folic acid supplement use to all women in the target group. Regular evaluation studies of these campaigns should be undertaken to develop strategies that are most effective.

It is difficult to obtain reliable estimates of the current incidence of NTDs in Ireland due to the absence of a comprehensive register of pregnancies affected by NTDs. Such a register is needed to evaluate the continuing effectiveness of national policy for prevention of NTDs. In addition, accurate data are needed on current levels of NTDs in Ireland prior to introduction of any new policy as recommended in the current report.

There is a need for ongoing monitoring of folic acid levels in foods and food supplements, and dietary intakes of folate (natural food folate and added folic acid) and blood folate levels in women of childbearing years as well as all other population groups. This is in order to provide the data required to assess the effectiveness and safety of the national policy for prevention of NTDs.

The policy for prevention of NTDs should be reviewed on a regular basis to assess its effectiveness and safety. This should be based on outcomes of monitoring of the rate of NTDs, compliance with advice on supplements, dietary intake and blood levels of folate for all population groups and updates on research related to safety.

This report presents two possible options to reduce risk of NTD-affected pregnancies in Ireland. For both options the available evidence shows that the levels of intake of folic acid that would occur would not increase the risk of adverse health effects in the population.

 

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