builds up, it appears to damage blood vessel walls and
promote clot formation in blood vessels.
Well-designed, reproducible research has shown
that people who have high levels of homocysteine in
the blood are more likely to develop cardiovascular
diseases such as coronary artery disease and stroke.
Clinical trials are underway to investigate the effects of
choline oh Alzeheimer’s disease, heart disease, and
fetal exposure to alcohol.
Description
Choline has not been the subject of as much
research as many of the other micronutrients. Not
until 1998 did the Food and Nutrition Board of the
United States Institute of Medicine (IOM), a part of
the National Academy of Sciences, declare choline to
be an essential nutrient and establishdietary guide-
linesfor it.
Normal choline requirements
The IOM has developed values called Dietary
Reference Intakes(DRIs) for many vitamins,miner-
als, and essential micronutrients. The DRIs consist of
three sets of numbers. The Recommended Dietary
Allowance (RDA) defines the average daily amount
of the nutrient needed to meet the health needs of
97–98% of the population. The Adequate Intake
(AI) is an estimate set when there is not enough infor-
mation to determine an RDA. The Tolerable Upper
Intake Level (UL) is the average maximum amount
that can be taken daily without risking negative side
effects. The DRIs are calculated for children, adult
men, adult women, pregnant women, andbreastfeed-
ingwomen.
The IOM has not set RDAs for choline because of
the scarcity of large, long-term dietary studies on this
micronutrient. Instead it has set AI levels for all age
groups based on the best observed and experimental
information available. For choline, the AI level was
established as the average daily amount needed to
prevent the development of a condition called fatty
liver. It may not be the amount needed for optimal
health. IAs and ULs for choline are measured inCholineAdequate Intake Tolerable upper intake
Age (mg) level (mg)
Children 0–6 mos. 125 Not established
Children 7–12 mos. 150 Not established
Children 1–3 yrs. 200 1,000
Children 4–8 yrs. 250 1,000
Children 9–13 yrs. 375 2,000
Boys 14–18 yrs. 550 3,000
Girls 14–18 yrs. 400 3,000
Men 19 yrs. 550 3,500
Women 19 yrs. 425 3,500
Pregnant women 450 3,500
Breastfeeding women 550 3,500
Food Choline (mg)
Beef liver, fried, 3 oz. 355
Wheat germ, toasted, 1 cup 172
Egg, 1 large 126
Cod, cooked, 3 oz. 71
Brussels sprouts, cooked, 2 cups 63
Broccoli, cooked, 1 cup 62
Peanut butter, 2 tbsp. 20
Milk chocolate, 1.5 oz. 20
mg milligram(Illustration by GGS Information Services/Thomson Gale.)
KEY TERMS
Amino acid—Molecules that are the basic building
blocks of proteins.
B-complex vitamins—A group of water-soluble
vitamins that often work together in the body.
These include thiamine (B 1 ), riboflavin (B 2 ), niacin
(B 3 ), pantothenic acid (B 5 ), pyridoxine (B 6 ), biotin
(B 7 or vitamin H), folate/folic acid (B 9 ), and coba-
lamin (B 12 ).
Dietary fiber—Also known as roughage or bulk.
Insoluble fiber moves through the digestive system
almost undigested and gives bulk to stools. Solu-
ble fiber dissolves in water and helps keep stools
soft.
Fatty liver—A condition in which liver cells accu-
mulate fat. The condition is associated with alcohol
abuse, obesity, and pregnancy and can result in
serious damage to the liver.
Neurotransmitter—One of a group of chemicals
secreted by a nerve cell (neuron) to carry a chem-
ical message to another nerve cell, often as a way of
transmitting a nerve impulse. Examples of neuro-
transmitters include acetylcholine, dopamine,
serotonin, and norepinephrine.
Triglycerides—A type of fat found in the blood.
High levels of triglycerides can increase the risk of
coronary artery disease.
Water-soluble vitamin—A vitamin that dissolves
in water and can be removed from the body in
urine.Choline