CHOLINE (phosphatidyl choline, lecithin)
Choline is important for cell growth, being an essential part of cell membranes.
The functions in the body include:
– Serves as a source for methyl groups for the biosynthesis of other compounds.
– Involved in one carbon metabolism with vitamins B12, folate, ethanol amine, and betaine (betaine formation requires choline).
– Betaine is a major donor of methyl groups for the methylation cycle.
– Is a major component of cell membranes as phosphatidyl choline.
– Phosphatidyl choline is involved in cholesterol and lipoprotein metabolism.
The choline molecule is part both phosphatidlycholine and sphingomyelin, important in cell membranes. As the precursor of acetylcholine this molecule is vital for nerve conduction, memory, and muscle control.
In the liver, fat and cholesterol are packaged into VLDL (very low density lipoproteins) for transport in the blood to tissues where they are needed. Phosphatidylcholine is required to make VLDL and without it fat and cholesterol accumulate in the liver.
SYMPTOMS OF DEFICIENCY
Liver dysfunction, including hepatitis and cirrhosis, and a fatty liver can be seen in extreme choline deficient states. Due to its role in cell membranes and nerve conduction, those deficient may have depression or memory loss, Alzheimer’s, and/or dementia. It has been used in Huntington’s chorea, tourette’s and cerebellar ataxia, seizures, and schizophrenia. It is unclear if deficiency actually causes these conditions, but it may be involved.
The most important role seems to be during pregnancy in the prevention of neural tube defects, and for adequate nutrition as part of infant formulas.
Due to the role in the methylation cycle, this nutrient in states of long term deficiency will be related to cardiovascular issues (arteriosclerosis, MI’s, stroke etc.) and increased cancer risk.
Beef liver (3 ozs) 355
Wheat germ (1cup) 172
Egg (1) 126
Fish (3 oz) 60-70
Beef (3 oz) 67
Brussel sprouts (1 cup) 63
Broccoli (1 cup) 62
Milk (1 cup) 20-40
Peanut butter (2 TBS) 20
Supplements of choline salts are available. Phosphatidylcholine and lecithin are only about 13% choline, thus about 4 grams would provide 500 mg choline.
SAFETY AND TOXICITY
No adverse effects have been seen with intakes up to 10 grams a day in adults. At 20 grams a day of choline as choline salts, excess cholinergic stimulation has been seen with increased salivation, sweating, nausea, dizziness, depression, and EKG changes. No symptoms other than upset stomach were noted when doses of choline were up to 100 grams a day. Obviously at high intakes there will be additional high caloric intake that may have it’s own problems. Moderation is recommended.
Teens and adults 550
TOLERABLE UPPER LIMITS
Infants unknown (1 gram likely ok)
Teens/ adults 3
Since methotrexate inhibits dihydrofolate reductase and thus limits methyl groups, additional choline can be helpful.
Given the high content in meats and eggs, vegetarians who do not consume eggs, should supplement choline.
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