Choline is easily absorbed from the intestines and is one of the only vitamins that crosses the blood-brain barrier into the spinal fluid to be involved directly in brain chemical metabolism. Choline is referred to as the "memory" vitamin, as it is an important part of the neurotransmitter acetylcholine.

Sources: Choline is present in all living cells and is widely distributed in plants and animals. Humans can synthesize choline from the amino acid glycine. The highest amount of choline is present in lecithin, usually obtained from soybeans. Other good sources include egg yolk, brewer’s yeast, wheat germ, fish, peanuts, some leafy greens, and liver and other organ meats. Choline is probably also manufactured by intestinal bacteria.

Functions: Choline as phosphatidylcholine, is a basic component of soy lecithin and thereby helps in the emulsification of fats and cholesterol in the body, by helping form smaller fat globules in the blood and aiding the transport of fats through the smaller vasculature and in and out of the cells. Choline is combined with fatty acids glycerol and phosphate to make lecithin (see more on lecithin in Chapter 4, Lipids), an important part of cell membranes.

Choline is also an integral part of the neurotransmitter acetylcholine. Its availability preserves the integrity of the electrical transmission across the gaps between nerves, and this helps the flow of electrical energy within the nervous system. It is also important to the health of the myelin sheaths covering the nerve fibers. Choline helps the liver and gallbladder function and is vital to brain chemistry, as it seems to aid thinking capacity and memory.

Uses: There are a great many uses for this important B vitamin. Choline may be helpful in the treatment of nerve conduction problems, memory deficiencies, muscle twitching, heart palpitations, and Alzheimer’s disease, where it seems to help brain function and slow the progression of the disease. Evidence has been mixed, however, as to effectiveness of phosphatidylcholine/lecithin treatment for Alzheimer’s disease; it has certainly not been shown to be a great panacea.

Choline has also been used for many kinds of liver and kidney problems, especially hepatitis and cirrhosis, by improving fat emulsification, transport, and utilization. It may actually help with general body detoxification by "decongesting" the liver of excess fats. Choline has been helpful in reducing some side effects of the phenothiazine drugs, which may cause abnormal facial muscle twitching and spasms, a syndrome called "tardive dyskinesia." It probably works by increasing acetylcholine function, thus promoting the transmission functions at nerve synapses. Recently, purified egg lecithin, which contains choline, has been used in the treatment of AIDS.

Other possible uses for choline are for headaches, dizziness, insomnia, constipation, glaucoma and other eye problems, abnormal ear noises such as tinnitis (ringing), hypoglycemia, and alcohol problems. Choline may be helpful for fatigue, and athletes have benefited from choline supplementation. With high cholesterol and high blood pressure, two important factors in cardiovascular disease, phosphatidylcholine (lecithin) may be helpful in reducing the progression of atherosclerosis. It seems to be effective as a fat and cholesterol emulsifier, and supplementation has been shown to reduce some gallstones. Choline has also been used with some benefit in stroke patients.