Choline
Choline
Definition
Choline is a nutrient required by the body. It does not meet the classic definition of a vitamin because the body makes some choline, but not enough to support health. The remainder must be acquired through diet. For practical purposes, choline is grouped with the B-complex vitamins because it is a water-soluble compound that performs some functions similar to these vitamins.
Purpose
Choline has several functions in the body. It is incorporated into the fat (lipid)-containing structures in cell membranes, and is necessary for the formation of certain signaling chemicals made by cells to activate other molecules. Choline is also necessary for the formation of acetylcholine. Acetylcholine is a neuro-transmitter that transfers information from nerves to muscles. Acetylcholine is also thought to be important to memory and learning in the brain. Finally, choline, like several other B vitamins, is active in the metabolic pathway that breaks down homocysteine and removes it from the body. Homocysteine is an amino acid that circulates in the blood. When too much homocysteine
Choline
| Age | Adequate Intake(mg) | Tolerable upper intake 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.)
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 establish dietary guidelines for it.
Normal choline requirements
The IOM has developed values called Dietary Reference Intakes (DRIs) for many vitamins, minerals, 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
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 (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7 or vitamin H), folate/folic acid (B9), and coba-lamin (B12).
Dietary fiber— Also known as roughage or bulk. Insoluble fiber moves through the digestive system almost undigested and gives bulk to stools. Soluble fiber dissolves in water and helps keep stools soft.
Fatty liver— A condition in which liver cells accumulate 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 chemical 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.
97–98% of the population. The Adequate Intake (AI) is an estimate set when there is not enough information 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, and breastfeeding women.
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 in milligrams (mg). The following list gives the recommended AL and UL levels of choline for each age group.
- children birth–6 months: AI 125 mg; UL not established. All choline should come from breast milk and infant formula or infant food.
- children 7–12 months: AI 150 mg; UL not established. All choline should come from food, not dietary supplements.
- children 1–3 years: AI 200 mg; UL 1,000 mg
- children 4–8 years: AI 250 mg; UL 1,000 mg
- children 9–13 years: RDA 375 mg; UL 2,000 mg
- boys 14–18 years: IA 550 mg; UL 3,000 mg
- girls 14–18 years: IA 400 mg; UL 3,000 mg
- adult men age 19 and older: RDA 550 mg; UL 3,500 mg
- adult women age 19 and older: RDA 425 mg; UL 3,500 mg
- pregnant women all ages: RDA 450 mg; UL 3,500 mg
- breastfeeding women all ages: RDA 550 mg; UL 3,500 mg
Sources of choline
Research suggests that the body makes only between 10% and 20% of the choline it needs to maintain health. The rest comes from diet. Foods rich in choline include beef liver, egg yolks, peanuts, and soybeans. Most choline in foods is in the form of phosphatidylcholine, which is also known as lecithin. Much less information is available about the choline content of specific foods than is available for other nutrients. Most people can meet the AI levels of choline through their normal diet. Some foods that have been analyzed for choline are listed below.
- beef liver, 3 ounces fried: 355 mg
- wheat germ, 1 cup toasted: 172 mg
- egg, 1 large: 126 mg (choline is concentrated in the yolk)
- cod, 3 ounces cooked: 71 mg
- Brussels sprouts, 2 cup cooked: 63 mg
- broccoli, 1 cup cooked: 62 mg
- peanut butter, 2 Tablespoons: 20 mg
- milk chocolate, 1.5 ounces: 20 mg
Choline chloride and choline bitartrate are also sold as a dietary supplements Choline is also found in dietary supplements marketed as lecithin. Soybeans are the most common source for lethicin in dietary supplements. These supplements contain a much smaller and more variable amount of choline than choline chloride or choline bitartrate supplements. Consumers should read the lethicin labels carefully. Some children’s multivitamins also contain choline.
Precautions
Moderate choline deficiency is associated with an increase in the blood levels of homocysteine. High levels of this molecule are known to increase the risk of cardiovascular disease. Extreme choline deficiency can result in a condition called fatty liver. Fat accumulates in liver cells where, in the absence of choline, it cannot be packaged and transported through the body. As a result, fats in the blood called triglycerides increase, creating an increased risk of heart disease and other health problems. Choline deficiency in pregnant women appears to have a negative effect on the development of the fetal brain and may cause learning, memory, and attention problems for affected children later in life.
Large excesses (10 g or more) of choline can cause nausea and extreme sweating. However, the most noticeable symptom of excess is the development of a highly unpleasant fishy body odor that results from the excretion of a choline breakdown product from the skin, urine, and breath. Large doses of choline dietary supplements do not appear to improve either physical or mental performance, nor do they appear to confer any specific health benefits.
Interactions
Methotrexate, a drug used to treat cancer, psoriasis, and rheumatoid arthritis causes choline deficiency in laboratory animals. Individuals taking this drug should discuss possible side effects with their physician. Choline also is involved in many of the same metabolic pathways as other B-complex vitamins. Deficiencies or excesses of any of these B vitamins may potentially alter choline metabolism .
Complications
No complications are expected when choline is taken in amounts equal to or exceeding the AI level. Doses much higher than the UL level have been tolerated without any obvious serious negative side effects (but also without any observed benefits).
Parental concerns
Animal studies suggest that choline has a positive effect in stimulating the developing brain of the fetus and that choline supplements given after birth may offset some of the effects of fetal alcohol exposure. Some Dietary supplement sellers have hyped these results, calling choline a miracle brain supplement or a genius supplement. Pregnant and breastfeeding women do need to eat a diet that provides adequate intake of choline, but should not be taken in by claims that choline supplements will increase the intelligence of their baby. As of 2007, these choline studies had only been done on rats where “learning” and “genius” were related to negotiating a laboratory maze. It remains to be seen if or how these findings relate to brain development in children.
Resources
BOOKS
Brown, Paul. “Choline, Inositol, and Related Nutrients” In Encyclopedia of Food and Culture Solomon H. Katz, ed. New York: Charles Scribner’s Sons, 2003.
Wildman, Robert E. C., ed. Handbook of Nutraceuticals and Functional Foods 2nd ed. Boca Raton, FL: CRC/Taylor &Francis, 2007.
PERIODICALS
Thomas, Jennifer D., Jeremy S. Biane, Kelly A. O”Bryan, et al. “Choline Supplementation Following Third-Trimester Equivalent Alcohol Exposure Attenuates Behavioral Alterations in Rats.& rdquo; Behavioral Neuroscience121, no. 1 (Feb 2007):120–30.
ORGANIZATIONS
Linus Pauling Institute. Oregon State University, 571 Weniger Hall, Corvallis, OR 97331-6512. Telephone: (541) 717-5075. Fax: (541) 737-5077. Website: http://lpi.oregonstate.edu>
OTHER
Higdon, Jane. “Choline.” Linus Pauling Institute-Oregon State University, November 25, 2003. <http://lpi.oregonstate.edu/infocenter/othernuts/choline>
PDR Health. “Choline.” undated, accessed April 27, 2007. <http://www.whfoods.com/>
Whfoods.org. “Choline” World”s Healthiest Foods, undated, accessed April 22, 2007. <http://www.whfoods.com/>
Helen M. Davidson
choline
Choline is synthesized in the body, and it is a ubiquitous component of cell membranes and therefore occurs in all foods, so that dietary deficiency is unknown. Deficiency has been observed in patients on long‐term total parenteral nutrition, suggesting that the ability to synthesize choline is inadequate to meet requirements without some intake. There is no evidence on which to base estimates of requirements; the US/Canadian adequate intake is 550 mg for men and 425 for women.