Choline, a water-soluble compound that is now classified as a B vitamin, first gained acceptance as an essential nutrient in 1998, according to nutritionist Elson Haas, M.D. At that time – acknowledging that humans must obtain choline from their diets to remain healthy – the Food and Nutrition Board established dietary reference intakes for this vitamin. As a component of several other important molecules, choline enjoys a ubiquitous presence in the body. Although minimum dietary requirements for choline are now well-established, dosages for specific conditions are less well-defined. Ask your doctor about the appropriate dose for you.
The Linus Pauling Institute at Oregon State University cites several physiologic roles for choline. As part of the phospholipids phosphatidylcholine and sphingomyelin, choline lends flexibility and integrity to the membranes of every cell in your body. Phospholipids also provide the mechanism for transporting cholesterol and triglycerides through your bloodstream. Phosphatidylcholine and sphingomyelin serve as precursors for signaling molecules, which allow your cells to coordinate their activities with those of surrounding cells. Choline is the precursor for acetylcholine, an important neurotransmitter. Finally, choline is a “methyl donor,” which allows it to participate in a number of crucial metabolic pathways.
Homocysteine is an amino acid which has been linked to heart disease. A study published in the July 2005 issue of “The American Journal of Clinical Nutrition” showed that daily supplementation of 2.6 g of choline effectively reduced homocysteine levels in 26 test subjects. Choline has also been evaluated for treating Alzheimer’s disease and other degenerative neurologic diseases, but no benefits have been demonstrated in these conditions, according to a 2003 Cochrane Database Review. However, the studies included in this review employed large doses of lecithin, a soy product containing variable levels of choline.
Choline’s chemical properties make it an intriguing prospect for treating a variety of medical conditions. Dr. Haas reports that choline, in daily doses of 500 to 1,000 mg, could be useful in liver diseases, such as hepatitis, fatty liver and cirrhosis, and in alcoholism, gallstones and AIDS. Furthermore, says Haas, athletic performance could be enhanced by choline supplementation. However, there is insufficient scientific evidence to show that choline is useful for any of these conditions.
Considerations, Recommendations and Precautions
Choline is an essential element in human nutrition, and deficiency can lead to fatigue, fatty liver, memory problems, muscle damage and poor immune function. Good dietary sources include soybeans, fish, egg yolks, wheat germ, liver, fish and brewer’s yeast. Daily requirements for choline vary from 125 mg for infants to 550 mg for adult males and lactating females. Choline doses of 10 g to 15 g daily can lead to vomiting, sweating, excessive salivation, fishy body odor and decreased blood pressure. Thus, the Food and Nutrition Board has established a tolerable upper limit for choline at 3.5 g for adults. Ask your doctor if you should take choline supplements.