Choline Present in all living cells, choline is another B-complex vitamin. It is synthesized from two amino acids, methionine and serine, with help from vitamin B12 and folic acid. Choline works with inositol, another lipotropic dietary factor, to prevent fat from building up in the liver and to shuttle fat into cells to be burned for energy. Choline is involved in the formation of the neurotransmitter acetylcholine in the body. If acetylcholine is reduced in the nervous system, fatigue may set in. Because acetylcholine is the most abundant neurotransmitter in the body, acting every time we think or move, it’s not surprising that low levels would lead to fatigue. Additionally, choline plays a central role in many other physiological pathways, including the cell membrane signaling involved in brain function and the methyl-group metabolism involved in hormone and energy metabolism. Researchers at MIT studied runners before and after the Boston Marathon and found a 40 percent drop in their plasma choline concentrations. They don’t know why this happened; however, they speculated that choline is used up during exercise to produce acetylcholine. Once choline is depleted, there’s a corresponding drop in acetylcholine production, and when production falls off, the ability to do muscular work falls off. A 2008 review published in the International Journal of Sport Nutrition and Exercise Metabolism pointed out that strenuous and prolonged physical activity may decrease circulating choline stores. Supplementing with choline prevents this, and may even improve endurance. The longer and harder you train, the more choline you use, and possibly use up. Choline is best absorbed when taken as phosphatidylcholine (PC), which is the body’s natural reservoir of choline and is also available as a supplement. PC is the major building block for all cell membranes, and it supports cell, tissue, and organ functions. Supplementing with PC helps maintain sufficient choline reserves for good health. You can also boost absorption by taking PC with phosphatidylserine (PS), another key building block for cell membranes. PS dietary supplements also may help you improve your athletic performance by suppressing cortisol, a potent, catabolic (breakdown) stress hormone. Too much cortisol in the body, which can result from intense workouts, may have negative effects on your training, performance, and physique. Research has shown that short-term oral supplementation of 750 milligrams per day of phosphatidylserine for 10 days improves exercise capacity during high-intensity cycling and increases running performance. Supplementing with PS is a natural, drug-free choice for athletes who want to overcome the effects of exercise-induced stress. Most vitamin supplements contain choline, and you should make sure to consume at least the DRI for choline daily. The effective dosage in sport studies is 0.2 gram of phosphatidylcholine per kilogram of body mass. This does not need to be any kind of loading strategy but can just be a maintenance program. The effective dosages for phosphatidylserine in exercise studies range from 300 to 800 milligrams per day for 10 to 15 days.