SACN - Folate and Disease Prevention
On 12th December 2006, the government's advisory committee, SACN, published a report on Folate and Disease Prevention, alongside which the FSA launched a consultation on options for improving folate intake in the population.
The report arises from a request from government that SACN (the Scientific Advisory Committee on Nutrition) should revisit the evidence on folates and health, to establish whether there has been a change in the strength of the evidence since the report published by COMA in 2000.
The report reaffirms COMA’s conclusion in the earlier report that there is a need, on balance, for introduction in the UK of mandatory fortification of flour with folic acid. They recommend a level of 300µgrams/100g flour. SACN’s recommendation is strengthened by the fact that there is now supportive evidence from elsewhere in the world, where mandatory fortification has been introduced, demonstrating substantial reductions in the incidence of NTD-affected pregnancies. Furthermore, there is also evidence of widespread marginal status of folate in the UK population (especially in young women and elderly people), which could be rectified by fortification of the food supply.
SACN also reaffirms the importance of folic acid supplementation for women who may become pregnant, especially as young women in the UK have a relatively high prevalence of low folate status.
Following a meeting of the FSA board on 7th December 2006, the Agency is now consulting on four possible options designed to increase folate intake of young women. These need not be mutually exclusive, and could be developed in combination.
Option 1 – Continue with the current policy of advice to women
Option 2 – Increase the effort to encourage young women to take folic acid supplements (folic acid a synthetic form of the vitamin folate, used in supplements and as a food fortificant) and changes to diet to increase the consumption of folate-rich foods
Option 3 – Encourage industry to fortify more foods with folic acid on a voluntary basis
Option 4 – Recommend the mandatory fortification of bread or flour with folic acid
The FSA is seeking the views of all stakeholders, including consumers, industry and health charities before making a recommendation to the minister.
Background to the Report
B vitamins intakes and status
- NDNS indicates average folate intakes to be above the RNI for all age groups but blood folate levels indicated poor status in young women (8% of those aged 19-24 and 4% of those aged 25-34) and older people (16% of institutionalised, 8% of free living people aged 65).
- Intakes of vitamin B6 and B12 were adequate but 5-10% of those aged 65 years have biochemical evidence of vitamin B12-deficiency (identified causes include malabsorption and pernicious anaemia).
- Low intakes of riboflavin and marginal riboflavin status were widespread in all age groups, particularly in women, girls, and boys.
Folate and NTDs: expected benefit of fortification of flour with folic acid
- Uptake of the recommendation for pregnant women to consume a 400µg/day supplement of folic acid prior to conception and until 12th week of pregnancy is not clear, but about 50% of mothers who report planning their pregnancy take folic acid supplements or modify their diet to increase intake (this is less likely amongst young mums and those from the most socio-economically deprived areas). But about 50% of pregnancies are unplanned and to be effective, the supplement has to be taken around the time of conception.
- It is estimated that there were at least 551-631 NTD-affected pregnancies in 2002 in the UK (incidence has changed little over the 1990s).
- Countries that have instituted folic acid fortification policies have seen reductions in NTDs of around 27-50%.
- COMA previously estimated that mandatory fortification of flour with folic acid at the recommended level (240 µg/100g) would reduce the incidence of NTD-affected pregnancies in the UK by 41%.
- Other possible benefits of the mandatory fortification include a reduced risk of CVD, certain cancers, bone disease and slower age-related cognitive decline but RCTs (randomised controlled trials) are needed to substantiate these claims.
- The suggested level of fortification by COMA was based on an overestimation of the flour content of bread (assumed to be over 70%). This is now realised to be 60% and to achieve the recommended increase in intake, flour would need to be fortified with 280µg folic acid/100g.
- The degree of overage (the practice of adding more than the recommended level to allow for losses during storage) in the amount of folic acid added to foods is an important consideration in determining the level to be used in the UK (in the USA average folic acid intake has increased after fortification by more than twice that originally intended).
Masking B12 deficiency in the elderly
- Intakes of folic acid above 1000µg could delay diagnosis of vitamin B12-deficiency in older people, and possibly cause irreversible neurological damage. Assuming a prevalence of deficiency of 5-10%, 2921-5844 older people in the UK could be at risk of vitamin B12-deficiency progressing, undiagnosed. The proportion of these that could develop neurological damage is unknown, though it is thought to be very low.
- No data are available on trends in the incidence of vitamin B12-deficiency, or for any related neurological damage, from countries that have introduced mandatory fortification of flour with folic acid.
- The B12 deficiency in older people is linked to malabsorption rather than dietary intake. Fortifying flour with B12 to improve status in the elderly is not feasible as doses to combat malabsorption would be in considerable excess of the RNI and the effect of population exposure to such high doses of vitamin B12 is not known.
- The recommendation for all women who could become pregnant to take 400µg/d folic acid prior to conception and until the twelfth week of pregnancy still stands, and is reaffirmed by the SACN review.
- Mandatory fortification of flour with folic acid should be introduced in the UK but the amount and form should be considered in the context of issues such as overage, use of vitamin supplements and control of voluntary fortification of other foods.
- The incidence, prevalence and management strategy for vitamin B12-deficiency in older people should be assessed, irrespective of whether the mandatory fortification of flour with folic acid is introduced. Better diagnostic indices need to be developed.
The full report is available on the SACN website.
Details of the FSA consultation are available here.
Last reviewed July 2009. Next review due January 2013.
- © British Nutrition Foundation 2009