title: Effect of age on changes in plasma, erythrocyte, and urinary B-6 vitamers after an oral vitamin B-6 load.
abstract: We investigated the effect of age on indices of vitamin B-6 metabolism in 36 fasting males aged 25-35, 45-55, and 65-75 y who ingested 17.15 mumol vitamin B-6. There were no significant differences among groups in dietary vitamin B-6 intake, base-line erythrocyte pyridoxal 5'-phosphate (PLP), and total vitamin B-6 concentrations, and 24-h and base-line urinary excretion of total vitamin B-6 and 4-pyridoxic acid (4-PA). Base-line plasma PLP and total vitamin B-6 were higher (p less than 0.05) in the youngest group. Increased serum alkaline phosphatase (AP) and decreased dietary vitamin B-6 intake were correlated with decreased base-line plasma PLP and total vitamin B-6. Changes in plasma and erythrocyte PLP concentrations and excretion of 4-PA and total vitamin B-6 postload were not different among groups. Indices of vitamin B-6 absorption, phosphorylation, and excretion were not affected by age.
authors.affiliation: Department of Food, Nutrition and Institution Administration, University of Maryland, College Park, MD 20742.
authors.forename: A K
authors.initials: AK
authors.lastname: Kant
authors.forename: P B
authors.initials: PB
authors.lastname: Moser-Veillon
authors.forename: R D
authors.initials: RD
authors.lastname: Reynolds
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D004912:Erythrocytes / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011732:Pyridoxal Phosphate / Q000097:blood; D011735:Pyridoxic Acid / Q000652:urine; D011736:Pyridoxine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D012016:Reference Values
chemical_list: D011735:Pyridoxic Acid; D011732:Pyridoxal Phosphate; D011736:Pyridoxine