LONDON — The United Kingdom and the European Union should join 81 countries, including the United States, in mandating folic acid fortification in food such as flour, according to a study published online Jan. 31 in Public Health Reviews.
The study may be found here.
Folic acid, a B vitamin, has been shown to prevent birth defects of the brain and spine known as neural tube defects. A tolerable upper intake level of 1 mg of folate per day has been an obstacle to mandatory fortification, but the scientific basis for setting that level is flawed, according to the study led by Queen Mary University of London and the University of London. The upper intake level thus should be removed, allaying unjustified concerns of folic acid fortification, according to the study.
“Failing to fortify flour with folic acid to prevent neural tube defects is like having a polio vaccine and not using it,” said Sir Nicholas Wald, DSc, founding director of the Wolfson Institute of Preventive Medicine at Queen Mary University of London. “Every day in the U.K., 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.”
Anencephaly and spina bifida, collectively known as neural tube defects, affect 1 in every 500 to 1,000 pregnancies. Since the U.S. Food and Drug Administration made folic acid fortification mandatory in most flours, including wheat flour, in 1998, the rates of neural tube defects have dropped nationwide by 35%, according to the March of Dimes.
No European Union country has implemented mandatory folic acid fortification, and rates of neural tube defects in the E.U. did not decline between 1991 and 2011, according to the study in Public Health Reviews.
“It is tragic that, while N.T.D.s can be prevented by increasing the consumption of folic acid in the population, this is not being achieved in practice in many parts of the world,” the study said.
The U.S. Institute of Medicine, now known as the National Academy of Sciences, originally recommended the upper limit of 1 mg of folate per day. The U.K. Scientific Advisory Committee on Nutrition accepted the recommendation.
The Institute of Medicine, when deciding upon an upper limit, considered the possible problem of neuropathy in people who were treated with folic acid when they instead were deficient in vitamin B12. The Institute of Medicine thought folic acid might “mask” a diagnosis of B12 deficiency.
However, the Institute of Medicine analyzed studies that mainly happened half a century ago, a period when folate deficiency could not be distinguished from B12 deficiency, according to the study in Public Health Reviews. The likelihood of masking an incorrect diagnosis disappeared in the last half of the 20th century when specific assays for folate and vitamin B12 deficiencies were introduced.
In the United Kingdom, white flour already is fortified with iron, calcium, niacin and thiamin.
“From 1998, when the United States introduced mandatory folic acid fortification, to 2017, an estimated 3,000 neural tube defects could have been prevented if the U.K. had adopted the same level of fortification as in the U.S.,” said Joan Morris, Ph.D., a professor of medical statistics at Queen Mary University of London and co-author of the study. “It’s a completely avoidable tragedy.”