Table 3.

Urinary excretion of betaine after a single dose (period A) or multiple doses (period C) of oral betaine in 12 healthy subjects.

Parameter	Mean ± s.d.	Range
Period A
24 h urinary excretion (mmol)	1.338 ± 1.111	0.153–4.324
% of oral dose (%)	4.0 ± 3.4	;0.4–13.1
CLR (l h−1 kg−1)	0.0044 ± 0.0037	0.0004–0.0139
% of total plasma CL (%)	5.3 ± 3.9	0.5–14.3
Period C
24 h urinary excretion (mmol)	4.361 ± 2.105	0.756–7.444
CLR (l h−1 kg−1)	0.0045 ± 0.0022	0.0006–0.0086

CL_R, renal clearance.