Folic acid should be added to flour to cut the risk of birth defects such as spina bifida, experts have recommended.
Under the plan, all bread would be made with folic acid-fortified flour
The Expert Advisory Group on Nutrition said it supports bringing in mandatory fortification.
The Food Standards Agency (FSA) will now launch a consultation to see if the public supports the move.
However, there is concern that adding the vitamin to flour could harm some elderly patients, as it could mask a deficiency in the B12 vitamin.
The FSA will set out four options in its consultation:
- Continue with the current situation where women trying to get pregnant and those in the early stages should take 400 micrograms a day
- Increase efforts to encourage young women to boost their folic acid intake
- Encourage the food industry to fortify more foods with folic acid
- Back mandatory fortification of bread or flour
The FSA will make a recommendation to ministers in May 2007, following the consultation.
Rosemary Hignett, head of nutrition of the FSA, said it was a complex issue.
But she added: "This consultation is an opportunity for consumers, industry, health charities and other stakeholders to express their views and opinions on this issue."
Folic acid supplements are already recommended for women who are pregnant or planning a pregnancy to prevent neural tube defects.
However, research suggests that only half of such women adhere to this advice.
Also, up to half of pregnancies are unplanned, meaning women may miss the opportunity.
Each year between 500 and 600 babies in the UK are reported to have neural tube defects. It is thought as many as 900 pregnancies a year are affected, but many are aborted.
But the concern over adding the B vitamin to flour, and therefore to everyone's diets, is that it could mask B12 deficiency.
Up to 10% of those aged 65 and older have borderline B12 levels and could tip into deficiency.
In extreme cases, this can cause irreversible damage to the nervous system, called subacute combined degeneration of the cord.
The Scientific Advisory Committee on Nutrition (SACN) first recommended that folic acid should be added to flour in 2000, but the government wanted more evidence to support the suggestion.
The committee has since looked at the US, Canada and Chile where folic acid has been added to flour since 1998.
The number of neural tube defects in babies in those countries has fallen by between 25 and 50% but there has been no rise in the number of elderly people affected by B12 deficiency.
Professor Alan Jackson, chairman of the SACN, said: "The clear benefits [of adding folic acid to flour] have to be balanced against the theoretical risk."
Andrew Russell, chief executive of the Association for Spina Bifida and Hydrocephalus, said: "It is the poorest and most educationally underprivileged women who are most at risk of a spina bifida pregnancy.
"Unfortunately relying on women to plan their pregnancies and take a folic acid supplement in advance is unrealistic in many cases."
But Hilary Powers, professor of nutritional biochemistry at the University of Sheffield, told the BBC's Today programme that was still a concern.
She added: "I'm also concerned there are unknown risks is a risk in increasing circulating levels of folic acid in the blood.
"One possible scenario is an increase in cells' capacity for division which could have implications for cancer risk."
Gordon Lishman director-general of Age Concern said: "There is a concern that an increase in folic acid could mask a vitamin B12 deficiency in older people and this could remain undetected and untreated."
"The recommendations from the FSA must take into account the implications introducing folic acid into flour would have for all age groups."