Monday is the final day for submissions on a Government proposal to make folic acid in bread compulsory.
The Ministry for Primary Industries is considering four options, ranging from mandatory fortification of most breads from September this year, to voluntary fortification.
The proposal was shelved in 2009 because of misgivings about possible side effects.
The New Zealand Association of Bakers supports the voluntary option, saying 34 types of bread are already fortified with folic acid.
The Paediatric Society says adding folic acid to bread could prevent between five and 10 people a year being born with conditions like spina bifida.
The Food Safety Minister will make a decision after considering submissions.