D-lactic acid and D-lactic acidosis in humans and domestic animals: a review.

D-lactic acid is quantitatively the minor isomer of lactic acid. It is main ly produced by the digestive microflora in the rumen or intestine and can a lso be synthetized from triose-phosphates by the liver. Its concentration i n healthy subjects remains low, much lower than L-lactic acid concentration , although its metabolism and/or elimination are much slower. When its synt hesis is increased, e.g. in diabetes mellitus, or when digestive fermentati ons are increased, D-lactic acid can be responsible for a severe metabolic acidosis, especially in the case of acute rumen acidosis in ruminants inges ting a high level of highly and rapidly fermentating glucides.