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Introduction to Choline
Introduction to Choline
Description
Choline can be synthesized in limited quantities in the liver and is therefore
not considered as a true vitamin. Mervyn (2) still considers the product as part
of the vitamin B group; Stanton and Geddes (3,4) both list the chemical as a vitamin
like substance. It is interesting to note that Geddes (3) does mention that it
is an essential vitamin for some animals and micro organisms. Finally, choline
is also classified as vitamin J (see
“Introduction to vitamins” ).
Choline is water soluble and its chemical name is trimethyl-2-hydroxyethylammoniumhydroxide. Other names for choline are amanitine and lipotropic factor.
Functionality
Choline forms an important part of lecithin (phosphatidylcholine) and other phospholipids. Lecithin is involved with the transport of fat within the body. Phospholipids in general form part of all lipid membranes.
Choline is one of the precursors for the neurotransmitter acethylcholine and is thus also involved in the conduction of nerve impulses along nerves and between nerves and muscles(2). Mindell (5) notes that as we age the effenciency of acethylcholine production declines and that the amount of neurotransmitters decline by up to 70%.
The compound is also a precursor for betaine, important in the metabolic process (in the methylating reaction) (2,3) and it stops fats accumulating in the liver.
Nielsen (1) provides a longer list of functionality; choline promotes the production of lecithin in the liver; It improves the functionalitiy of liver, gallbladder, adrenal glands, sex glands, heart and circulation; It strengthens capillary walls and improves circulation of blood in the eyes; It helps to form a brain substance which improves ones memory.
Factors affecting requirements
- Bioavailability
Choline is absorbed better when part of lecithin than on its own.
- inborn errors in metabolism
(Documentation not found)
- losses in food processing
(Documentation not found)
- vitamin/mineral relationship
the human body to produce choline, vitamins B12, B9 or Folic acid and the
amino acid methionine are required (Geddes3). Mindell (5) lists the same vitamins
but mentions the amino acid L-carnitine.
Usage
Stanton (4) classifies as myth the beliefs that choline supplement can calm
the nerves and prevent fat being deposited in unfashionable places. She also
observes that lecithin only has an effect on blood cholesterol if taken intravenously;
supplements taken orally has no effect (probably because it is not absorbed).
Geddes (3) further observes that some forms of choline may adversely affect
the activity of intestinal bacteria, interrupting production of other vitamins.
Mendell (5) on the other hand does not mention any reason not to take choline
as a supplement (phosphatidylcholine or phosphatidylinositol).
vitamin deficiency
In lab experiments on animals, induced deficiencies have caused fatty liver
and cirrhosis of the liver, along with increased cholesterol levels, higher
blood pressure and kidney damage. These results have not been repeated for humans
(3) (remember that what is a vital vitamin varies from animal to animal) and
Stanton reckons that provided a normal diet is followed, deficiency is not likely
(4).
Geddes (3) also mentions that choline deficiency has been linked to arteriosclerosis
and Alzheimer's disease.
Mervyn (2) has a list of deficiency symptoms which includes the above symptoms
as well as thrombosis and a reduced resistance to infection.
vitamin toxicity
Nielsen stated that toxic levels were not known below a daily dosage of 6000mg
(note that Nielsen's book is from 1981 and suggested dosage may be out of date).
This is supported by Mervyn who only mentions mild nausea as a reported complaint
(2).
vitamin therapy
Stanton (4) and Geddes (3) at best see no benefit from taking supplements.
Mendell sees no reason why not to (5). Nielsen (1) lists the following therapeutic
uses - treatment of disturbances of the blood circulation, the heart, the liver
and the gallbladder; treament of cataract and capillary damages in the eyes;
bad memory and hormonal imbalances. Mervyn (2) supplements this list with defined
diseases: angina, atherosclerosis, thrombosis, stroke, high blood-pressure,
alzheimer's disease, senile dementia. Nielsen (1) lists therapeutic dosages
in the range of 1000-2000mg.
Other uses(6)
E322 or lecithin is used bt the food industry to -
- Allow oils and fats to be combined with water (in margarine, ice cream)
- Increase loaf volume and soften the crumb of bread
- Protect vitamin A
- A reduction in the amount of cocoa butter used in chocolate
Dosage
Nielsen (1) reckoned 500-1000mg as a daily dosage. Mervyn (2) makes a similar
conclusion and also points out that the recommended daily intake (RDA) is difficult
to asses because of body synthesis.
Sources
Apart from taking a lecithin supplement (of which granules can give up to
3.4g/100g (2)), animal organs and egg the highest sources of choline:
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Source
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mg/100g
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Source
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mg/100g
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Desiccated liver
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2170
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Wheatgerm
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505
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Beef heart
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1720
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Nuts
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220
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Egg-yolk
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1700
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Fruits (citrus best)
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40-85
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Liver
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650
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Vegetables (green leaf best)
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40-80
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Beef stake
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600
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Milk
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30
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References:
- "Biologisk Regeneration" by Kurt Winberg Nielsen, 1981
- "Thorsons Complete Guide to Vitamins and Minerals" by Leonard
Mervyn, 2000
- "Vitamins & Minerals", published by Geddes and Grosset, 1999
- "Vitamins" by Rosemary Stanton, published 1999
- “Earl Mindell's Supplement Bible” by Earl Mindel, published 1999
- "E for Additives" by Maurice Hansen, 1987
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