Pyridoxine Deficiency in Congestive Heart Failure

Abstract
The presence of relative pyridoxine deficiency was determined by the occurrence of increased urinary xanthurenic acid following a 10 g tryptophan load. Under standard hospital conditions, 14 patients with congestive heart failure showed an elevated xanthurenic acid excretion. Repetition of the loading test after a 50 mg dose of pyridoxine HC1 resulted in restoration of xanthurenic acid excretion toward normal. Fourteen normal controls failed to show any significant change in xanthurenic acid excretion after a tryprophan load. The ability of pyridoxine to restore the normal response of the body to tryptophan is to be considered as biochemical evidence of a specific pyridoxine deficiency in patients with congestive heart failure.