Translations:Vitamin B6/42/en
Less severe cases present with metabolic disease associated with insufficient activity of the coenzyme pyridoxal 5' phosphate (PLP). The most prominent of the lesions is due to impaired tryptophan–niacin conversion. This can be detected based on urinary excretion of xanthurenic acid after an oral tryptophan load. Vitamin B6 deficiency can also result in impaired transsulfuration of methionine to cysteine. The PLP-dependent transaminases and glycogen phosphorylase provide the vitamin with its role in gluconeogenesis, so deprivation of vitamin B6 results in impaired glucose tolerance.