Two patients presented themselves with a hypochromic, microcytic anemia which was responsive to pyridoxine hydrochloride. One also had hemochromatosis and impaired iron utilization. A complete hematological response occurred on 2 occasions in the second patient. Hypochromasia and microcytosis persisted after hemoglobin values had returned to or near normal. A tryptophan-loading test in one case showed that the abnormal levels of hydroxykynurenine were corrected by pyridoxine therapy. The literature on pyridoxine-responsive anemia is reviewed, and it is suggested that a phosphorylating enzyme of pyridoxine may be implicated in this disease.
Bottomley SS. Pyridoxine-Responsive Anemia. JAMA. 1962;180(8):653-659. doi:10.1001/jama.1962.03050210015004