|Folic Acid May Prevent Cleft Lip and Palate
A new study finds that women who take folic acid supplements
early in their pregnancy can substantially reduce their baby’s
chances of being born with a facial cleft.
Researchers at the National Institute of Environmental Health
Sciences (NIEHS), part of the National Institutes of Health, found
that 0.4 milligrams (mg) a day of folic acid reduced by one third
the baby’s risk of isolated cleft lip (with or without cleft palate).
Folic acid is a B vitamin found in leafy vegetables, citrus fruits,
beans, and whole grains. It can also be taken as a vitamin supplement,
and it is added to flour and other fortified foods. The recommended
daily dietary allowance for folate for adults is 400 micrograms
or 0.4 mg.
“These findings provide further evidence of the benefits of folic
acid for women,” said Allen J. Wilcox, M.D., Ph.D., lead NIEHS
author on the new study published online in the British Medical
Journal. “We already know that folic acid reduces the risk
of neural tube defects, including spina bifida. Our research suggests
that folic acid also helps prevent facial clefts, another common
birth defect.” In the United States, about one in every 750 babies
is born with cleft lip and/or palate.
“Folic acid deficiency causes facial clefts in laboratory animals,
so we had a good reason to focus on folic acid in our clefts study,” said
Wilcox. “It was one of our main hypotheses.”
The researchers examined the association between facial clefts
and mothers’ intake of folic acid supplements, multivitamins, and
folates in diet. The researchers found that folic acid supplementation
of 400 micrograms or more per day reduced the risk of isolated
cleft lip with or without cleft palate by one-third, but had no
apparent effect on the risk of cleft palate alone.
“A mother’s nutrition during pregnancy is clearly an environmental
factor that can affect the health of her fetus,” said NIEHS Director
David A. Schwartz, M.D. The NIEHS researchers are continuing to
analyze their data for evidence of other environmental exposures
that increase the risk of facial clefts.
This population-based study was conducted in Norway, which has
one of the highest rates of facial clefts in Europe and does not
allow foods to be fortified with folic acid. The investigators
contacted all families of newborn infants with clefts (either cleft
lip with or without cleft palate (CLP) or cleft palate only (CPO))
born between 1996 and 2001 in Norway. The study included 377 babies
with CLP and 196 with CLO; as well as 763 control babies randomly
selected from all live births in Norway.
The researchers mailed two questionnaires to each of the mothers
participating in the study. The first questionnaire mailed soon
after delivery focused on general health information, including
demographics, reproductive history and information about environmental
exposures including smoking, alcohol and vitamins; whereas the
second questionnaire focused on nutrition and diet during the pregnancy.
Mothers who reported taking folic acid supplements and or multivitamins
were asked to send in their empty bottles or labels to confirm
The nutrition questionnaire included questions on mothers’ fruit
and vegetable consumption during the first three months of pregnancy.
The researchers estimated that 22 percent of isolated CLP cases
in Norway could be averted if all pregnant women took 0.4 mg of
folic acid per day.
In addition to funding from NIEHS, this research was supported
by the Johan Throne Holst Foundation for Nutrition Research, and
the Thematic Perinatal Nutrition at the Medical Facility of University
of Oslo, Norway. Researchers at the University of Bergen, the University
of Oslo, and the Departments of Plastic Surgery in Oslo and Bergen,
Norway, also contributed to this study.
The National Institute of Environmental Health Sciences (NIEHS),
a component of the National Institutes of Health, supports research
to understand the effects of the environment on human health.
For more information on environmental health topics, please visit
our website at http://www.niehs.nih.gov/.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.