Choline bitartrate combines choline with tartaric acid. It costs less than other choline forms and appears in many basic supplements. However, gut bacteria break down a portion of it before it enters your bloodstream, so you absorb less choline than from phosphatidylcholine or alpha-GPC.
People take it to help reach the Adequate Intake (AI) for choline. Choline supports neurotransmitter production, cell membrane integrity, and fat transport. Taking it with food reduces stomach upset.