B-Vitamins

The B-vitamins are eight water-soluble cofactors that between them run one-carbon metabolism, the citric-acid cycle and neurotransmitter synthesis. The Institute's 2021 material treats them through one specific compound and one general method.

Picamilon

Picamilon is niacin covalently joined to GABA. It exists to solve a specific problem: GABA taken orally does not meaningfully cross the blood-brain barrier, which makes plain GABA supplements largely pointless. Attached to niacin, the molecule crosses, and is then hydrolysed centrally into its two halves — GABA plus a vasodilator.

It is a neat illustration of the bioavailability theme running through this whole section: the same molecule, made useful by changing what it is attached to.

Picamilon was developed in the Soviet Union in 1969 and remains a medicine in Russia. In the United States the FDA determined in 2015 that it is not a lawful dietary ingredient, and it was removed from the market — it is a synthetic drug that was never a food.

"Read your urine"

The method paired with it. Because the B-vitamins are water-soluble and excess is excreted, the body gives a crude visible signal of saturation — riboflavin (B2) turns urine bright yellow-green within a few hours of a dose past requirement.

This is a real observation and a genuinely useful folk biomarker, and it should be understood for exactly what it is: it tells you that B2 is in excess. It says nothing about B12, folate, B6 or thiamine status, and it is not a saturation signal for the B-complex as a whole. Presented as such, it is a good heuristic. Extended past B2 it is false.

It echoes the T-0 method of the 2016 material: watch the body's readouts rather than trusting the number on the label.

The individual cautions worth knowing

B6 (pyridoxine) — the exception to "water-soluble means safe". Chronic intake above roughly 100 mg/day causes irreversible sensory peripheral neuropathy. This is the most under-recognised supplement toxicity in common use, and B6 is in most B-complexes and most energy drinks. Pyridoxal-5-phosphate (P5P) is the active form and is often assumed exempt; it is not established to be.
B3 (niacin) — the flush is harmless; sustained-release niacin at gram doses is hepatotoxic. Niacinamide does not flush and does not lower lipids.
B9 (folate) — masks the anaemia of B12 deficiency while the neurological damage proceeds. Check B12 first. See L-Methylfolate.
B12 — deficiency is common in vegans, in metformin users and after 60 through loss of intrinsic factor; the damage is neurological and can be permanent.
B1 (thiamine) — the deficiency to know is Wernicke's encephalopathy, in alcohol dependence and after bariatric surgery. See also the thiaminase warning under horsetail.