Fortifying flour with folic acid would be worthwhile for the health of the UK, recommend food and nutrition experts.
In the future, flour could have folic acid added to it
The Scientific Advisory Committee on Nutrition (SACN) says the overall benefits of increasing people's folate levels would outweigh any risks.
However, such a move might be harmful for some elderly patients deficient in another B group vitamin - B12.
To minimise this risk, fortification must be accompanied by measures to tackle B12 deficiency, they advise.
Benefits and risks
The concern is that by adding folic acid to food supplies cases of anaemia caused by B12 deficiency will be missed - folic acid supplementation can mask B12 deficiency.
B12 deficiency is particularly common among the elderly - up to 10% of those aged 65 and older have borderline B12 levels and could tip into deficiency, SACN estimates.
In extreme cases can cause irreversible damage to the nervous system, called subacute combined degeneration of the cord.
This can be prevented by giving those at risk extra vitamin B12.
Interested parties will now have eight weeks to comment on the recommendations before the committee produces its final report in the Spring to advise Government.
Folic acid supplements (400 micrograms per day) are already recommended for women who are pregnant or planning a pregnancy to reduce the risk of their baby developing growth problems of the brain or spinal cord, collectively called neural tube defects.
However, research suggests that only half of women planning a pregnancy or who are pregnant adhere to this advice.
Also, as many as 50% of pregnancies are unplanned, meaning women may miss the opportunity.
Each year around 500-600 babies are reported to have neural tube defects - often these disabilities are incompatible with life.
SACN estimates that adding folic acid to flour could cut this rate in half.
It might also have a benefit in cutting heart disease, it said, although it is too early to tell for sure.
Research has shown that folate, of which folic acid is a form, which is found in certain foods, cuts cardiovascular disease risk. Studies are ongoing to see if synthetic folic acid supplements do the same.
Lessons from abroad
Data also shows that people other than women of childbearing age may be deficient in folate and might benefit from consuming higher levels.
Some foods in the UK, such as bread, breakfast cereals and margarine, already contain added folic acid.
Other countries, including the US, Canada and Chile, have already made fortification of flour with folic acid mandatory.
In these countries, the neural tube defect rate has gone down, as has the risk of cardiovascular disease.
There have been reports that folic acid may be linked to certain cancers, but SACN looked at the available data and said there was no good evidence to suggest that this would be a problem if flour were to be fortified.
SACN chairman Professor Alan Jackson, who is professor of human nutrition at Southampton General Hospital, said: "Any possibility of masking the development of B12 deficiency has to be a matter of concern."
A spokeswoman from the British Nutrition Foundation said: "We agree with the recommendations.
"There is still a need to look at vitamin B12 deficiency. If we do not pick up on this it could be a problem, but we should be doing that anyway."
Andrew Russell of The Association for Spina Bifida and Hydrocephalus said: "This balanced report gives a wonderful opportunity to introduce a measure to benefit all UK women of child-bearing age and their families."