London, Jan 31 : The British government's decision not to implement a health recommendation - to fortify flour with folic acid - that led to death of or birth defects in thousands of babies, was based on a "flawed" analysis and "competely avoidable tragedy", claims a new study.
The current intake of folate -- 1 mg per day -- led to vitamin deficiency which caused neural tube defects of the brain, spine, or spinal cord among 1 in every 500-1,000 pregnancies in the country.
The study, appearing in the journal Public Health Reviews, showed there is no need for an upper limit of intake of folic acid.
"Failing to fortify flour with folic acid to prevent neural tube defects is like having a polio vaccine and not using it.
Every day in the UK, on average two women have a termination of pregnancy because of a neural tube defect and every week, two women give birth to an affected child," said lead author Sir Nicholas Wald, Professor at the Queen Mary University of London (QMUL).
In 1991, a Medical Research Council randomised trial showed that increasing folic acid intake immediately before and early in pregnancy prevented most cases of neural tube defects.
As a result, 81 countries, including the US since 1998, have introduced mandatory folic acid fortification of cereals, which has been found to reduce the prevalence of neural tube defects, without any evidence of harm.
In these, the number of neural tube defects has decreased by up to a half.
However, despite successive recommendations, Britain did not introduce mandatory fortification, partly on the basis of a study by the US Institute of Medicine, which claimed that higher doses of folic acid may lead to neurological damage.
If it had adopted the same level of fortification as in the US, that began in 1998, an estimated 3,000 neural tube defects could have been prevented, the researchers said.
"It's a completely avoidable tragedy," said co-author Joan Morris, Professor at the QMUL.
The new study finds no relationship between dose of folic acid and the development of neurological damage, the researchers said.
"With the upper limit removed there is no scientific or medical reason for delaying the introduction of mandatory folic acid fortification in the UK and other countries that have not yet adopted this proven public health intervention," Wald said.