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Adequate intake of folic acid by women during very early pregnancy can markedly reduce risk of the development of neural-tube defects (NTD). The effectiveness of advice to women to take folic acid supplements is limited, mainly because 50% of pregnancies are unplanned. However, mandatory folic acid food fortification programmes in North America have been very successful in reducing NTD rates. In Ireland higher rates of pregnancies are affected by NTD and the option of termination is illegal. Consequently, the much higher burden of disease makes primary prevention of NTD an important public health issue in Ireland. During 2006 a decision was taken in Ireland to initiate mandatory folic acid fortification of most bread to prevent NTD. Priority work was immediately undertaken to establish reliable and comprehensive baseline information on factors that will be affected by fortification. This information included data on: the national prevalence of pregnancies affected by NTD; the current extent of voluntary folic acid fortification of food on the Irish market and how it affects folic acid intakes; blood folate status indicators assessed for various subgroups of the Irish population. In addition, scientific developments that have arisen since 2006 relating to the risks and benefits of folic acid intake are under ongoing review. The present paper summarises the rationale for mandatory folic acid food fortification in Ireland and recent scientific developments relating to risks and benefits of folic acid intake. In this context, preliminary findings of baseline monitoring investigations in Ireland are considered.

Two probabilistic models were developed to estimate the acute and chronic exposure to fluoride of exclusively formula-fed infants aged 0-4 months as a result of the consumption of infant formula reconstituted with fluoridated tap water in Ireland. The estimates were based on calculated infant formula consumption and accepted body weight standards, together with reported concentrations of fluoride in infant formula powder and measured values for the fluoride content of water in Ireland. The mean acute exposure of infants to fluoride on any single day in areas served by 387 fluoridated water supplies was estimated to be between 0.11 and 0.14 mg/kg body weight depending on age group (95th percentiles 0.2 and 0.26 mg/kg b.w., respectively). These predicted intakes were well below the intake of fluoride associated with acute toxic effects, which is considered to be 5 mg fluoride (F(-))/kg body weight. The mean chronic exposure of infants to fluoride was estimated to be between 0.106 and 0.170 mg/kg b.w./day depending on body weight (95th percentiles 0.108 and 0.172 mg/kg b.w./day, respectively). This estimate described the average daily fluoride intake of infants during the first 4 months of life residing in the areas served by 226 water supplies that achieved an average yearly fluoride concentration below 1.03 mg/l. Dental fluorosis may be considered to be the only risk at these low doses and from our work it is estimated that there is a very low risk of moderate dental fluorosis of the permanent dentition in infants exposed to fluoride at these levels.