Choline is an essential, water-soluble nutrient, often associated with the B complex of vitamins though, strictly speaking, is not itself a vitamin. It is important for the structural integrity of cell membranes, lipid and cholesterol metabolism, and as a precursor for the neurotransmitter, acetylcholine, which is involved in muscle control, memory storage and other important biochemical functions.

      A RDI for choline has not been established by the FDA. The recent assessment for this nutrient from the National Academy of Sciences (NAS) is detailed in the table below. Please note the special considerations for the Tolerable Upper Intake Levels (UL) in footnote 5.

      Choline is widely distributed, with the highest concentration appearing in such foods as milk, liver, eggs, and peanuts.
      This nutrient is also synthesized in the body, but at a rate that is affected by the dietary intake of methionine, folate (folic acid) and vitamin B12. Sufficient intake of these nutrients alone, however, does not guarantee that sufficient choline will be produced. See the comments below on supplements for additional information.

      Natural choline deficiency is uncommon among healthy individuals with normal diets, particularly those that are adequate in the B complex vitamins. When inadequate amounts of choline are consumed, the most common result is liver damage, especially in adult men.
      Although not corroborated in humans, animal studies have reported additional health hazards from choline deficiency, including growth retardation, kidney dysfunction, bone abnormalities, and bleeding problems.

      Choline supplements are most commonly found in multivitamins, or in combination with B complex vitamins. Since this nutrient is naturally synthesized in the human body, there may be certain segments of the population that require less supplemental choline than others. In some cases, trained athletes may benefit from choline supplementation (see Current Issues below).
      It has been shown that adult men do not produce an adequate amount of choline, even with adequate dietary intake of methionine, folate (folic acid) and vitamin B12 (see Food Sources), and therefore require dietary or supplemental sources of this nutrient. There is insufficient data available to determine if women, children, and older individuals require dietary or supplemental choline.
      Animal studies, on the other hand, have corroborated these observations and suggest that males may have a higher requirement for dietary choline than women, though post-menopausal women (as demonstrated in animal models) may require dietary sources of this nutrient where their pre-menopausal counterparts may not.

      Health risks from choline are quite minimal unless amounts thousands of times greater than the Adequate Intake (AI) of this nutrient are consumed. The most common results from such excesses are hypotension (abnormally low blood pressure), trimethylaminuria (fish odor syndrome), and less commonly, liver toxicity.

      Exercise. Plasma choline levels have been shown to be significantly reduced after strenuous exercise, as demonstrated in studies among trained athletes. Supplementation of this nutrient has countered this effect, and has also resulted in modestly enhanced physical performance in some reports.
      Dementia. Choline has been used in some cases to treat symptoms of dementia in older individuals. Reports in animal models have suggested that choline can be used at earlier stages of life to minimize, or prevent the effects of memory loss later in life, though there have not yet been any studies to evaluate this effect in humans.
      Cardiovascular disease. Dietary and supplemental choline may have a correlation with risk reduction of cardiovascular disease. Some forms of this nutrient have demonstrated the ability to modestly reduce plasma cholesterol levels. Perhaps more significant are choline’s demonstrated effects on the lowering of high plasma homocysteine levels, a compound believed to be a significant factor in heart disease. One study reported a more significant effect than with folic acid (folate) treatment in this regard, in a younger individual with a genetic disorder (homocysteinuria) that elevated homocysteine levels. The prevalence of cardiovascular disease in the developed world would suggest the need for more research on the potential of choline as a possible risk reduction factor in this disease.
      Cancer. Although there have been no human studies, animal models have suggested that dietary deficiency of choline resulted in liver cancer, and increased sensitivity to cancer causing chemicals. The possibility exists that supplemental choline may have a role in the reduced risk of some forms of cancer, or perhaps the susceptibility to some forms of cancer, but much more research would be needed in this area to establish a positive causal relationship.