Choline is a water-soluble member of the group of B vitamins. It is not classed as a true vitamin because it is present in the body in larger amounts than are usually associated with these nutrients. There is no co-factor concerned with enzymic reactions or containing choline to be found.
Choline is defined as a lipotropic factor, which means that it prevents fats building up in the liver by solubilising them and transporting them to organs that require them. It is synthesised in the liver and is also present in compounds such as:
- choline bitartrate
- choline chloride
- phosphatidyl choline
Choline is a colourless crystalline substance associated primarily with the utilisation of fats and cholesterol in the body. Choline is measured in milligrams (mg).
The vitamin substance choline is synthesised in the liver in fairly limited quantities, but is available in most animal tissues and plants. Indeed, it is so widely available in foods that dietary deficiencies rarely occur. Choline usually occurs as a component of phospholipids which are complexes of fatty acids, phosphorus, sugar and choline. The most nutritious phospholipid is lecithin, which is also the richest source of choline. Some good food sources of choline are as follows:
|Animal and plant foods||Choline (mg)|
|32 g sunflower lecithin syrup||544|
|142 g raw beef liver||473|
|15 g soy lecithin granules||450|
|A cup of wheat germ||202|
|227 g cod fish||190|
|454 g broccoli||182|
|454 g cauliflower||177|
|Half a pound of chicken||150|
|Two cups (0.47 litres) firm tofu||142|
|A cup uncooked amaranth||135|
|30 g Brewer’s yeast||120|
|100 g Soybeans dry||116|
|Large hardboiled egg||113|
|A pound of spinach||113|
Average daily intake for a healthy adult is between 500 mg and 1000 mg. Since additional choline is made in the body it appears to be easy to obtain sufficient quantities of the nutrient.
Choline has a number of important functions in the body, relating primarily to its lipotropic activity. It is often referred to as an anti-fat agent and appears to be instrumental in the production of phospholipids and in the efficient transportation of fats in the blood.
The liver normally contains only 5 – 7% of its own weight as fat but without sufficient choline this proportion can be increased by as much as 50%. A fatty build-up of this nature in any of the vital organs can have serious health consequences. Diabetes, alcohol-related problems and protein deficiency are all linked to excess levels of fat in the liver. Research has demonstrated that choline supplementation can help to break down and clear accumulated deposits of fat in this organ.
Since it is water-soluble, choline is not stored in the body and the nutrient must therefore be derived from the diet on a daily basis, although the body is capable of making adequate supplies of choline from food materials. However, the fact that so many complaints and conditions respond well to choline supplementation suggests that the amounts synthesised by the body may not always be enough.
Most of the choline ingested in the diet is broken down by intestinal bacteria and then used as an emulsifier. Choline is constantly required by the body and is excreted in amounts of between 5 – 9 mg a day, depending on intake.
Choline’s solubility makes it slightly vulnerable in foods that are processed or those that are cooked in water, such as green-leafed and root vegetables.
Choline is generally very stable in egg yolk, meat, soya and sunflower lecithin granules and wheatgerm.
Like all B complex vitamins, it is affected to some extent by consumption of alcohol, smoking and prolonged use of drugs, including the contraceptive pill.
When there is a deficiency of choline, the fat content in the liver increases and hepatic cirrhosis can occur. Prolonged deficiency may encourage other conditions such as:
- high blood pressure
- senile dementia
- reduced resistance to infection
- high levels of blood fats and cholesterol
Although these symptoms of deficiency are serious they are uncommon because choline is so widely available in food and is constantly manufactured within the body. However, since this nutrient is so important to health, particularly in later life, careful attention should be paid to diet to ensure that it includes adequate sources of choline.
Inositol is linked with choline because of the fat fighting properties they have in common.
Inositol appears to complement the action of choline and so for maximum efficacy in controlling fat metabolism, both nutrients should be available in adequate quantities. Both are present in lecithin.
Folic acid, B12 and choline work together, participating in many of the body functions that are essential to general health and in particular to the transformation of RNA and DNA and the maintenance of healthy nerve function.