ABSTRACT D-Lactate is normally present in the blood of mammals at nanomolar
concentrations due to methylglyoxal metabolism; millimolar D-lactate concentrations can
arise due to excess gastrointestinal microbial production. Grain overload in ruminants, short-
bowel syndrome in humans, and diarrhea in calves can all result in profound D-lactic
acidemia, with remarkably similar neurological manifestations. In the past, D-lactate was
thought to be excreted mainly in the urine, and metabolized slowly by the enzyme D-α …