title: Differences in vitamin B6 status indicator responses between young and middle-aged women fed constant diets with two levels of vitamin B6.
abstract: The responses of adult women to two levels of vitamin B6, was conducted with five young and eight middle-aged subjects. A constant diet (2.3-2.4 mg vitamin B6 per day) was fed for four weeks followed by three weeks of the same diet supplemented with 8.0 mg pyridoxine. Plasma pyridoxal 5'-phosphate (PLP), plasma and urinary vitamin B6, and urinary 4-pyridoxic acid (4-PA) were determined. The older women had significantly lower plasma PLP, plasma and urinary vitamin B6 and slightly higher urinary 4-PA values on normal vitamin B6 intakes. With supplementation, only the difference in urinary total vitamin B6 remained significant. Tryptophan load tests revealed no significant between-group differences in xanthurenic acid or kynurenic acid excretion. These results demonstrate an age-related difference in vitamin B6 status indicators in women under controlled dietary intake of vitamin B6.
mesh_terms: D000328:Adult; D000367:Age Factors; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007736:Kynurenic Acid / Q000031:analogs & derivatives / Q000652:urine; D008875:Middle Aged; D011732:Pyridoxal Phosphate / Q000097:blood; D011735:Pyridoxic Acid / Q000652:urine; D011736:Pyridoxine / Q000378:metabolism*; D014364:Tryptophan; D014977:Xanthurenates
chemical_list: D004040:Dietary Carbohydrates; D014977:Xanthurenates; C028330:xanthurenic acid; D011735:Pyridoxic Acid; D011732:Pyridoxal Phosphate; D014364:Tryptophan; D007736:Kynurenic Acid; D011736:Pyridoxine