Survey of total folate intake at conception and assessment of impact of fortification

Abstract

Background. In view of plans for dietary fortification with folic acid, there is a need to reassess the advice being given in primary care. Patients and professionals may assume that fortification will make preconceptional folic acid supplementation unnecessary, but this is unlikely to be correct. Aim. To calculate the intake of total folic acid and folate at conception and to estimate the impact of fortification on the incidence of neural tube defect (NTD) conceptions.Design. An in-depth investigation of dietary folate intake of 18 women and a survey of preconception supplementation in a group of 130 women, including an assessment of the probable impact of mandatory fortification. Method. Dietary folate intake of six infertile women and 12 age-matched fertile controls was assessed using a 7-day weighed diet diary. Mean values for this group were used as an estimate of local dietary folate intake. Questionnaires about periconceptional intake of supplements that included folic acid in their formulation were given to newly pregnant women attending district midwife clinics, a series of women attending an assisted conception unit and a self-help group of lesbians who were either pregnant or planning a pregnancy. Results. Of the 18 women in the dietary study there was suboptimal dietary folate intake in all infertile subjects and in eight of 12 controls. An approximate value for the combined intake of dietary folate and folic acid in the larger survey (n5130) was calculated. We estimated that UK dietary fortification will double the number of pregnancies with adequate total folate intake. From previous data on folic acid intake and NTD births we estimate that this will prevent 226-343 conceptions per year in the UK from developing NTD malformations. Conclusions. Fortification should prevent approximately 226-343 conceptions a year from developing NTDs, but 45% of women will still have an inadequate total folate intake, unless supplementation levels improve.

A survey to estimate total nutrient intake at conception — Dietary and supplementary

“…Apart from folic acid, which is discussed in full elsewhere [39], the B vitamins have a general role in energy transfer and growth in the developing embryo [47]. Although the mean dietary intake of vitamins B1, 2, 3, 6 and 12 in our survey was above the RNI, there is evidence that some individuals may be genetically susceptible to borderline B vitamin levels with an increased risk of infertility [52,53] and spontaneous abortion [54].…”

“…These values were analysed using SPSS 11.5 for Windows to determine the statistical significance and the differences between the three subgroups (natural pregnancies, assisted pregnancies and lesbian pregnancies). Our data suggest that some women will not reach optimal folate (dietary folate plus folic acid) intake, even with supplementation, but this subject and possible solutions will be dealt with in a separate paper [39]. The value of fortification with other nutrients depends on the interpretation of the UK RNI and other standards that have been suggested.…”

“…We are assuming that, as is the case with folic acid, a good start to pregnancy is essential and that regimens that commence later in the pregnancy will have no beneficial effect [33]. As the topic of folic acid supplementation and the probable influence of dietary fortification with folic acid is a major area of research, controversy and political debate, our findings on dietary folate and folic acid supplementation will be dealt with in a separate paper [39].…”

Folates, folic acid and preconception care – a review

“…Politicians have commented, however, that implementing this recommendation is ‘low on our list of priorities’. Based on my own research, 20 , 21 data from North America 22 and data from the Wolfson Institute, 23 mandatory fortification would result in 300 healthy infants per year being born that are currently mostly terminated for neural tube defect following antenatal screening by ultrasound. However, folic acid fortification remains a little controversial ( Table 1 ) and was halted in 2007 due to concerns that it might increase the risk of colorectal cancer.…”