Any guesses on how much choline would be required for human supplementation based on this in vitro result?
I'll try to answer my own question here.
The culture medium concentrations that were tested are 2.5mg/L and 5mg/L, which converts to roughly 25 uM/L and 50 uM/L. ( uM = micro Mole ,
The molar mass of choline is roughly 100g/M )
The normal serum concentrations of choline are between 6 and 15 uM/L.
Based on the in vitro result, we might try to push serum concentrations up towards those 25 and 50 numbers. But this looks like it would require a huge dose. In this paper,
Effect of Oral CDP-Choline on Plasma Choline and Uridine Levels in Humans, the largest dose of citicoline given to a subject was 4000mg. In this case, the choline serum concentration was raised from roughly 11uM/L to 18uM/L.
Lower doses were also tested and from the look of the graph in the paper, peak serum concentration is proportional to dose. So we might expect an 8000mg citicoline dose to give us a 25uM/L serum concentration.
We are talking crazy amounts here! Apart from this study, I've only seen citicoline trialed at doses of 2000mg and below, so there is no information on safety I'm aware of. Without more information, this is not doable, especially considering the slim chance that our POTS has the same cause as the case that was studied.
I'll continue to trial citicoline at much lower doses. Hopefully it'll just take a bit more time.