Choline (Bitartrate)

Choline is an essential nutrient, formally recognised as such relatively recently. It is not a vitamin, though it was once assigned the number B4, a designation now abandoned.

Eggs are the standout source, with a couple of yolks supplying a substantial share of daily requirement. Liver, meat, fish and soy also contribute. Survey data suggests a considerable proportion of people fall short of adequate intake, particularly those avoiding eggs.

Choline bitartrate is the cheapest supplemental form, roughly 41 per cent choline by weight. It is perfectly adequate for meeting nutritional requirements. What it is not good at is raising brain choline, which is the job people usually buy it for, and that distinction is the whole point of this entry.

Choline serves three main roles: it is the precursor to acetylcholine, a component of phosphatidylcholine in cell membranes, and a methyl donor once converted to betaine.

The problem with bitartrate for cognitive purposes is transport. Free choline crosses the blood-brain barrier poorly and inefficiently, so raising blood choline does not translate proportionally into raising brain choline.

Alpha-GPC and citicoline solve this by delivering choline in forms that cross more readily. That is precisely why they cost more and why they dominate nootropic formulas while bitartrate dominates cheap ones. Choline is also converted by gut bacteria into a compound that has attracted cardiovascular research interest, and bitartrate produces more of this than the alternatives.

Choline's essentiality is well established, and its roles in liver function, membrane structure and methylation are not in question. Meeting adequate intake matters, and bitartrate does that job cheaply.

For cognitive outcomes, trials of choline bitartrate in healthy adults have generally found little benefit, consistent with the transport limitation. Studies using alpha-GPC or citicoline have fared better.

The practical conclusion is simple: buy bitartrate if you want to meet your choline requirement cheaply, and buy alpha-GPC or citicoline if you want a cognitive effect. Buying bitartrate for focus is spending money on the wrong form.

Choline is safe at intakes near requirement. The tolerable upper intake is 3.5 g daily for adults, which is well above what supplements typically provide.

Exceeding that produces a distinctive fishy body odour, along with sweating, nausea and lowered blood pressure. The odour comes from a compound produced when gut bacteria metabolise excess choline.

That same compound has attracted research interest in relation to cardiovascular risk markers. The question is unresolved rather than settled, but it argues against indefinite high-dose supplementation without a reason.