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Chapter 2
Folic Acid
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
An Ounce of Prevention
Addressing Health Issues
of Adolescents and Young Adults
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Chapter 2
Folic Acid
The miracle vitamin?
Practical problem:
What do I need to know about folic acid
and how it affects health and fetal development?
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Key concepts
1. Folic acid
• Vitamin B9
• Sources
• Functions
2. Importance prior to conception
• Reduction vs. prevention of birth defects
• Impact on general health
• Folic acid timing
• Neural tube closure
• Daily dietary recommendations
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Objectives
1. Define folic acid.
2. Analyze sources of folic acid and the daily
dietary recommendation.
3. Simulate neural tube closure.
4. Summarize the characteristics of the two
major neural tube defects, spina bifida and
anencephaly.
5. Explain other health benefits of folic acid.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Rationale
Evidence suggests that taking folic acid
before conception and during critical
periods of fetal development decreases
the risk for certain physical birth defects.
This chapter provides general information
about folic acid, its role in our bodies and
how it reduces the chance for neural tube
defects. Information about neural tube
defects is also presented.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
What is folic acid?
The synthetic form
of folate, vitamin B9.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Sources of folate
Food sources
• Green vegetables
• Orange juice
• Beans, nuts
• Liver
• Yeast breads
• Fruits
• Eggs
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Sources of folic acid
1. Foods enriched with
folic acid — mainly
grain products
2. Vitamins —
the synthetic form
of folate
Enriched
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
U.S. dietary sources of
folate and folic acid
Richest Sources
Highest Contributors
•Orange juice
•White bread
•Super-fortified cereals
•Dried beans
•Eggs
•Liver
•Liver
•Super-fortified cereals
•Cold cereals
•Asparagus
•Spinach
•Instant breakfast
•Bran/granola cereals
•Broccoli
•Avocados
Adapted from American Journal of Clinical Nutrition vol. 50(3), Subar et al, 1989.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Causes of low folic acid levels
• Alcohol
• Diet low in folate
or folic acid
• Peak times of cell
proliferation
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Folate or folic acid?
• Folic acid, the synthetic form, has
almost 100 percent bioavailability
• Dietary folate
 can be destroyed by cooking
processing and storage
 is not absorbed as well as
synthetic folic acid
 has 50 percent bioavailability
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Benefits of folic acid
during pregnancy
• Prevention of neural tube defects
• Protective factor to reduce the risk of other birth
defects
• Positive effects for pregnancy term and prenatal
growth
• Decreases homocysteine effect on the placenta
• placental abruption
• clogging of placental blood vessels
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Folic acid also
benefits heart health
Taking folic acid can help to reduce the risks
for cardiovascular disease — for everyone.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Two major roles of folic acid
1. Nucleic acid synthesis and cell division
• DNA is made up of
nucleic acids
• DNA replicates and divides
during cell division
• Cell division develops
and maintains our bodies
• Pregnancy is a time
of rapid cell division
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Two major roles of folic acid
2. Methylation
• Methylation is a
biochemical process
that turns genes “off.”
• Methylation is essential
for normal development.
• Methionine is a naturally
occurring amino acid.
• Homocysteine, also an
amino acid, is produced
in the body during the
metabolism of
methionine.
An Ounce of Prevention
• As homocysteine
increases, the risk of
heart disease
increases.
• When folic acid levels
are low,
homocysteine levels
increase.
• Folic acid helps break
down and reduce
homocysteine in the
body.
 2000, 2005, 2011 The Curators of the University of Missouri
Who should take folic acid?
Everyone!
Folic acid reduces
the chance for
birth defects and
pregnancy problems,
and helps prevent
cardiovascular disease.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
How much folic acid?
• Females of childbearing
capability: 400 micrograms
400
micrograms
• Females who have had one
child with a neural tube
defect: 4 milligrams
(10 x 400 micrograms)
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
When to take folic acid?
• Before and after conception
• Throughout pregnancy
• While breastfeeding
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Development of the spinal cord
Source: Answering Your Questions About Spina Bifida, a guide from The Spina Bifida Program, Department of General Pediatrics. Children’s National
Medical Center, 1995. Washington, D.C.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Neural tube defects (NTD)
The neural tube
 is an embryonic structure that will become the
brain and spinal cord
 develops first as a flat layer of cells that roll into
a cylinder and “zip” shut
Neural tube defects
 affect the brain or spine, and
occur when the tube fails to close
 are the second most common birth defect
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Features of neural tube development
and neural tube defects
Reprinted by permission from The New England Journal of Medicine, 341[1999]:1509-1519.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Neural tube defects (NTD)
Spina Bifida occurs when a baby’s spine does not form properly. Part
of the spinal cord may be outside the bones of the spine (vertebrae)
and is often not properly formed. This can lead to varying degrees of
muscle weakness, paralysis, loss of sensation in the leg and/or poor
bladder and bowel control. Some babies with spina bifida also develop
fluid on the brain (hydrocephalus), which occasionally causes brain
damage.
Anencephaly is a neural tube defect in which the top part of the skull
and brain fail to form properly. Babies with anencephaly may be
miscarried, stillborn or die shortly after birth.
Encephalocele is another less common neural tube defect. This
occurs when part of a baby’s skull does not form properly and part of
the brain is outside of the skull. Babies with this type of neural tube
defect usually die. Babies who survive may have physical and mental
handicaps.
What You Should Know About Folic Acid, for parents who have lost a pregancy or had a child with spina bifida,
anencephaly, or encephalocele. Children’s Hospital Medical Center of Akron, fourth printing, 1999.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Spina bifida
• Can lead to paralysis and kidney malfunction
• The location, type and severity of the defect
affects the level of impairment
• Requires surgery 24 to 48 hours after birth
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Complication of spina bifida:
Hydrocephalus
• Excess fluid around the brain
• Surgical procedure inserts
shunt to drain fluid into the
abdomen
• Early treatment improves
chances for normal cognitive
development
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Anencephaly
• Partial or complete
absence of the brain
• There are no options
for surgical correction
• Infants are usually stillborn
or die shortly after birth
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Encephalocele
• Brain tissue herniates
into a sac protruding
from the skull opening
• Rarer than other
neural tube defects
• Methods of surgical
correction and
level of function vary
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Causes of neural tube defects
• Chromosomal abnormality
• Genetic syndrome
• Multifactorial inheritance
• combination of genetic and environmental factors
• 90 percent are multifactorial
• genetic and environmental factors not exactly
known
• research continues, including the connection with
folic acid
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Who is at risk for
neural tube defects?
• All couples have some risk
• Factors that contribute to a higher risk
• English or Irish ancestry
• Family history of neural tube defects
• Low levels of folic acid
• Poor diet
• Maternal hyperthermia: exposure to high temperatures
through tanning beds, saunas, hot tubs and high fever
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Reduce risks for
neural tube defects
• Avoid high temperatures
• Maintain a healthy diet and weight
• Take folic acid daily
before becoming pregnant
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Remember:
• The neural tube closes by day 28.
• Most pregnancies are unplanned.
• The neural tube closes before many
women know they are pregnant.
• Get into the folic acid habit now.
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri
Key learning activities
• Analyze labels
• Simulate neural tube closure
• Develop a marketing tool
• Add it Up folate in food calculation
• Folic Acid Bingo
• E-learning activity: Folic Acid Jeopardy
An Ounce of Prevention
 2000, 2005, 2011 The Curators of the University of Missouri