In 1998 the US FDA required the addition of folic acid to enriched breads, flours, cereals, and other grain products to increase folic acid intake in the whole population. Birth defects have declined by 26 percent since 1998.
Calls have been getting louder in the UK, with some analysts now saying it is a question of 'when' and not 'if' the UK government introduces compulsory fortification of some flour products with folic acid.
According to American voluntary health agency March of Dimes, over eight million babies are born worldwide with birth defects; at least 3.3 million of under-fives die because of serious birth defects every year, while the majority of those who survive may be mentally and physically disabled for life.
The new retrospective cohort study, published in the journal Pediatrics looked at 2841 infants born with spina bifida between 1998 and 2001.
"Infants with spina bifida experienced a significantly improved first-year survival rate of 92 per cent during the period of mandatory folic acid fortification, compared with a 90 per cent survival rate for those born before fortification," reported lead author Kirk Bol from the Colorado Department of Public Health and Environment.
The authors admit that there are certain limitations which may affect the data, most noteworthy being the lack of information on the frequency of abortions due to the presence of a birth defect.
In an accompanying editorial, Robert Brent and Godfrey Oakley, said that the study was well-planned and well-performed.
"The investigators' conclusions are biologically plausible...These data indicate that a child born with spina bifida in the United States is 10 times as likely to die in the first five years as the average newborn child," said Brent and Oakley.
Although the mechanism of folic acid protection during pregnancy is not known, it has been proposed to be due to its role in nucleic acid synthesis and/or the metabolism of homocysteine to methionine.
The authors of the study concluded: "As survival of NTD-affected infants improves, health care, education, and family support must expand to meet their needs."
The editorial comment from Brent and Oakley called for an increase in the level of folic acid fortification, echoing calls from the same scientists only last September in an earlier volume of the same journal.
Studies have shown that folic acid is more easily absorbed from fortified foods (85 per cent) and supplements (100 per cent) than the folate found naturally in foods (50 per cent).