Bread should be fortified with folic acid to reduce birth defects such as spina bifida, a watchdog says.
Under the plan, all bread would be made with folic acid-fortified flour
The recommendation was agreed by the Food Standards Agency and will now be passed to ministers for approval.
Research shows folic acid cuts the risk of neural tube defects, which affect hundreds of pregnancies a year.
But there is concern that adding the vitamin to bread could harm some elderly patients, as it could mask a deficiency in B12 vitamin.
In extreme cases, this can cause irreversible damage to the nervous system.
Folic acid is a source of folate, a vitamin found in broccoli, sprouts, peas, chickpeas, brown rice and fruit.
It is important for the development of the spine in the first stages of pregnancy and women are advised to eat extra folic acid when trying to get pregnant.
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.
Mandatory fortification has already been introduced in the US, Canada and Chile, where it cut defect rates by up to half.
The evidence has prompted the FSA board to agree to the measure after rejecting it five years ago.
The board said new controls on the addition of folic acid to breakfast cereals and low-fat spreads by manufacturers will be essential if the measure is brought in.
FSA chair Dame Deirdre Hutton told the FSA board meeting in Nottingham that she supported the measure.
"I don't believe it is the ultimate solution. I believe it is the best pragmatic solution we can get."
The FSA board could not agree on whether folic acid should be added to bread or to flour, which would mean it would also be included in biscuits and cakes, although this technicality will be resolved next month.
And it called for more debate on how products fortified with folic acid should be labelled.
Andrew Russell, chief executive of The Association for Spina Bifida and Hydrocephalus, said: "It is a rare opportunity to benefit from a vitamin, and significantly improve public health.
"Demographics show that it is the poorest and most educationally underprivileged women who are most at risk of a spina bifida pregnancy."
But Dr Frankie Philips is a spokesperson for the British Dietetic Association, said she was still concerned.
"We need to be very careful, because although increasing the amount of folic acid that people have in their diet through fortification is useful, we need to be aware that there are risks."