Food fortification cuts cases of spina bifida in Canada
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《英国医生杂志》
The fortification of a nation抯 food with folic acid dramatically reduces the incidence of spina bifida and other neural tube defects. This benefit occurs without masking vitamin B-12 deficiency in elderly people, a theoretical risk of fortifying food with folic acid.
These were the findings of Canadian researchers who studied the population in Newfoundland, an area with historically high rates of neural tube defects (BMC Pregnancy and Childbirth 2004;4:20). They found that the rate of such defects was 78% lower after fortification. They conclude that fortifying food with folic acid at the current levels should continue in Canada.
In 1998 fortification of white flour, pasta, and cornmeal with folic acid was imposed in Canada to increase the intake of folic acid of all women of childbearing age. White flour is fortified with folic acid at a level of 0.15 mg per 100 g of flour. This was expected to increase intake of folic acid among women of childbearing age by about 100 micrograms a day. This level of fortification is conservative, not only to protect the non-targeted population from high concentrations but also because raising intake to the recommended level for women at low risk, 400 micrograms a day, is almost impossible.
The main concern about fortification was that it might mask vitamin B-12 deficiency, a condition affecting 10% to 15% of people aged over 60 years. Greater amounts of folic acid can remove the haematological signs of vitamin B-12 deficiency and so delay diagnosis and treatment.
Because of this concern Dr Catherine McCourt of the Health Surveillance and Epidemiology Division within the Population and Public Health Branch of Health Canada, Ottawa, Ontario, and colleagues undertook their comprehensive, population based study. The study looked at women aged 19-44 years and people aged over 65 from November 1997 to March 1998 and from November 2000 to March 2001.
The proportion of neural tube defects fell from an average of 4.36 in every 1000 births before fortification to 0.96 in 1000 births after fortification. The average dietary intake of folic acid after fortification was 70 micrograms a day in women aged 19-44 years and 74 micrograms a day in elderly people. (The proportion of women aged 19-44 years taking a vitamin supplement containing folic acid increased from 17% to 28%.)
Although significant increases of folate in serum and in red blood cells were shown in elderly people after fortification, indices typical of vitamin B-12 deficiency in elderly people did not change significantly, and no evidence was shown of improved folate status masking haematological manifestations of vitamin B-12 deficiency.
The authors write, "Based on these findings, mandatory food fortification in Canada should continue at the current levels. Public education regarding folic acid supplement use by women of childbearing age should also continue."(London Robert Short)
These were the findings of Canadian researchers who studied the population in Newfoundland, an area with historically high rates of neural tube defects (BMC Pregnancy and Childbirth 2004;4:20). They found that the rate of such defects was 78% lower after fortification. They conclude that fortifying food with folic acid at the current levels should continue in Canada.
In 1998 fortification of white flour, pasta, and cornmeal with folic acid was imposed in Canada to increase the intake of folic acid of all women of childbearing age. White flour is fortified with folic acid at a level of 0.15 mg per 100 g of flour. This was expected to increase intake of folic acid among women of childbearing age by about 100 micrograms a day. This level of fortification is conservative, not only to protect the non-targeted population from high concentrations but also because raising intake to the recommended level for women at low risk, 400 micrograms a day, is almost impossible.
The main concern about fortification was that it might mask vitamin B-12 deficiency, a condition affecting 10% to 15% of people aged over 60 years. Greater amounts of folic acid can remove the haematological signs of vitamin B-12 deficiency and so delay diagnosis and treatment.
Because of this concern Dr Catherine McCourt of the Health Surveillance and Epidemiology Division within the Population and Public Health Branch of Health Canada, Ottawa, Ontario, and colleagues undertook their comprehensive, population based study. The study looked at women aged 19-44 years and people aged over 65 from November 1997 to March 1998 and from November 2000 to March 2001.
The proportion of neural tube defects fell from an average of 4.36 in every 1000 births before fortification to 0.96 in 1000 births after fortification. The average dietary intake of folic acid after fortification was 70 micrograms a day in women aged 19-44 years and 74 micrograms a day in elderly people. (The proportion of women aged 19-44 years taking a vitamin supplement containing folic acid increased from 17% to 28%.)
Although significant increases of folate in serum and in red blood cells were shown in elderly people after fortification, indices typical of vitamin B-12 deficiency in elderly people did not change significantly, and no evidence was shown of improved folate status masking haematological manifestations of vitamin B-12 deficiency.
The authors write, "Based on these findings, mandatory food fortification in Canada should continue at the current levels. Public education regarding folic acid supplement use by women of childbearing age should also continue."(London Robert Short)