Doctors have today called on the government to allow folic acid to be added to flour in a bid to cut birth defects.

Experts writing in medical journal the Lancet say the measure could cut the number of pregnancies affected by neural tube defect, also known as spina bifida, by around 400 a year.

Plans to force bakers to add folic acid to bread are currently on hold amid concern that the proposal could increase the risk of other health problems.

The Food Standards Agency, which previously backed the proposals, has indicated that a decision is to be delayed until chief medical officers consider recent publications on the issue.

But in today's Lancet, medical experts led by Dr Roger Bayston, of the Association for Spina Bifida and Hydrocephalus, claim that two recent papers suggesting a link between folic acid and other health concerns have been misinterpreted.

They point out that a study which has been used to suggest a connection between folic acid and adenoma - glandular growths - does not show that the vitamin poses a risk, as it refers to benign tumours and not cancerous ones.

A second report on the association between folic acid and an increase in colorectal cancer also fails to produce evidence of a link, the doctors suggest.

The doctors conclude: "The FSA and the chief medical officer can be confident in recommending that the UK government introduce the mandatory fortification of flour, which could prevent about 400 pregnancies affected by neural tube defects each year, reducing both the number of terminations of pregnancy and of children born with these defects."