September 2004 — Adding folic acid to food can dramatically reduce the incidence of
spina bifida and other birth defects. A study, published today in BMC
Pregnancy and Childbirth, shows that the proportion of babies born with
neural tube defects in the province of Newfoundland and Labrador
dropped by 78% after the Canadian Government directed that folic acid
must be added to flour, cornmeal and pasta. The study supports the
continuation of this food fortification strategy.
The way that
folic acid works to reduce the risk of neural tube defects in
developing babies is poorly understood, yet the evidence that this
vitamin is of benefit is clear. Since 1992, many health organizations
have recommended that women take 400 micrograms of supplemental folic
acid per day before conception and in the early weeks of pregnancy.
In 1998 the Canadian Government introduced the mandatory fortification
of some foods with folic acid to help ensure that all women of
childbearing age increased their intake of this vitamin.
Catherine McCourt, from the Population and Public Health Branch, Health
Canada, and her colleagues from other Canadian institutes studied the
effects of this folic acid fortification in women and babies from
Newfoundland and Labrador. Historically, this province has one of the
highest rates of neural tube defects in North America.
researchers found that the food fortification increased the dietary
intake of folic acid in the studied women of childbearing age by 70
micrograms per day, on average. The blood folate levels of these women
and of the sample of seniors 65 years and older increased significantly.
incidence of neural tube defects in the province reduced from an
average of 4.36 defects per 1000 births between 1991 and 1997, prior to
fortification, to an average of 0.96 defects per 1000 births between
1998 and 2001, once fortification was introduced.
Over the study
period, the number of women aged between 19 and 44 who took folic acid
supplements rose significantly from 17% to 28%. It was not possible in
this study to determine the separate contributions of food
fortification and supplement use to the decline in neural tube defects.
Therefore, the authors stress that, "public education regarding folic
acid supplement use by women of childbearing age should continue."
has been some debate about whether an increased intake of folic acid
could mask the symptoms of vitamin B12 deficiency, a disorder that
affects 10-15% of the population over 60. Yet this study provided no
evidence for a deterioration in vitamin B12 status in seniors, and no
evidence that improved levels of blood folate masked this vitamin
Source : BioMed Central Limited