Urinary excretion of indices of propionyl overload (3-hydroxypropionate [3-OH-prop], propionylglycine [PropGlycine], methylcitrate [MeCitrate]) and pimelic in urine samples from 50 normal subjects (black bars), the VLCAD patients (gray bars; ten samples collected over 12 months), and ten patients with propionic acidemia (white bars).