Orally administered betaine has an acute and dose-dependent effect on serum betaine and plasma homocysteine concentrations in healthy humans

Schwab U, Törrönen A, Meririnne E, Saarinen M, Alfthan G, Aro A, Uusitupa M · The Journal of Nutrition

The pharmacokinetic picture behind daily dosing: single 3 g and 6 g doses lowered plasma homocysteine within about 2 hours, the 1 g dose did not, and after the 6 g dose concentrations stayed low across the full 24 hours of monitoring.

Population

Healthy normal-weight volunteers, randomised double-blind crossover

Intervention

Single oral betaine doses of 1, 3 and 6 g after an overnight fast

Comparator

The three doses against each other, 24-hour sampling

Limitations

Ten volunteers, single doses, biochemical endpoints; a crossover pharmacokinetic study rather than a trial of any health outcome.