title: Response of vitamin B-6 content of muscle to changes in vitamin B-6 intake in men.
abstract: Previous reports indicated that in growing rats the vitamin B-6 pool in muscle was relatively stable during deficiency but increased in response to increased vitamin B-6 intake. To determine whether human muscle would show a similar response 10 college-aged males received a low vitamin B-6 diet (1.76 mumol/d) for 6 wk followed by 6 wk on a self-selected diet supplemented with 0.98 mmol pyridoxine HCl/d. During depletion, excretion of pyridoxic acid rapidly adjusted to approximate the intake. Plasma pyridoxal phosphate concentrations at the end of the baseline, depletion, and supplementation periods were 81 +/- 51, 9 +/- 3, and 455 +/- 129 nmol/L, respectively, whereas muscle concentrations were 21 +/- 9, 20 +/- 4, and 25 +/- 7 nmol/g, respectively and total vitamin B-6 in muscle was 28 +/- 10, 27 +/- 4, and 35 +/- 10 nmol/g, respectively. These data provide further confirmation that the vitamin B-6 pools in skeletal muscle are resistant to depletion. They also demonstrate that in humans with constant body weight, vitamin B-6 supplementation is not associated with marked increases in vitamin B-6 in muscle.
authors.affiliation: Biochemistry Department, Fort Wayne State Developmental Center, IN.
authors.forename: S P
authors.initials: SP
authors.lastname: Coburn
authors.forename: P J
authors.initials: PJ
authors.lastname: Ziegler
authors.forename: D L
authors.initials: DL
authors.lastname: Costill
authors.forename: J D
authors.initials: JD
authors.lastname: Mahuren
authors.forename: W J
authors.initials: WJ
authors.lastname: Fink
authors.forename: W E
authors.initials: WE
authors.lastname: Schaltenbrand
authors.forename: T A
authors.initials: TA
authors.lastname: Pauly
authors.forename: D R
authors.initials: DR
authors.lastname: Pearson
authors.forename: P S
authors.initials: PS
authors.lastname: Conn
authors.forename: T R
authors.initials: TR
authors.lastname: Guilarte
mesh_terms: D000328:Adult; D001219:Aspartate Aminotransferases / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D008297:Male; D009132:Muscles / Q000737:chemistry*; D011732:Pyridoxal Phosphate / Q000097:blood; D011736:Pyridoxine / Q000008:administration & dosage* / Q000032:analysis / Q000097:blood / Q000652:urine; D026681:Vitamin B 6 Deficiency / Q000097:blood / Q000201:enzymology
chemical_list: D011732:Pyridoxal Phosphate; D001219:Aspartate Aminotransferases; D011736:Pyridoxine