Metabolism of vitamin B6 by human kidney

Janos Zempleni, Werner Kübler

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

A continuous intravenous pyridoxine-infusion (dose = 100 mg PN·HCl τ = 6 h) was given to 10 healthy male volunteers (aged between 23 and 32). Concentration-time curves of B6-metabolites in urine and blood plasma were observed over a period of 240 hours. From these curves biokinetic parameters were calculated. Renal clearances (ml/min/1.73 m2) were 257.5 ± 92.1 (pyridoxine), 249.8 ± 48.2 (4-pyridoxic acid), and 20.1 ± 6.0 (pyridoxal). Rate constants of elimination (h-1) obtained by non-linear regression of the excretion curves were 1.231 ± 0.877 (pyridoxine), 0.314 ± 0.118 (kα) and 0.048 ± 0.070 (kβ) (4-pyridoxic acid), and 0.653 ± 0.360 (pyridoxal). The main part of the infused pyridoxine was eliminated in the form of metabolites (63.7 ± 6.4% for 4-pyridoxic acid, 3.3 ± 0.9% for pyridoxal); only 6.7 ± 1.8% was excreted unchanged. The proportion of 4-pyridoxic acid within each miction increased from 53.0 to 100.0%. Our data indicate a very effective metabolism of the physiologically inactive pyridoxine. An enzyme induction suggested by the increasing proportion of 4-pyridoxic acid cannot be excluded. Large doses of vitamin B6 are excreted rapidly via the kidney, with the excretion of pyridoxine and 4-pyridoxic acid being enhanced by tubular secretion.

Original languageEnglish (US)
Pages (from-to)187-192
Number of pages6
JournalNutrition Research
Volume15
Issue number2
DOIs
StatePublished - Jan 1 1995

Fingerprint

Pyridoxic Acid
Pyridoxine
Vitamin B 6
Pyridoxal
Kidney
Enzyme Induction
Intravenous Infusions
Healthy Volunteers
Urine

Keywords

  • 4-Pyridoxic acid
  • Kidney
  • Kinetics
  • Pyridoxal
  • Pyridoxine
  • Renal Clearance

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism
  • Nutrition and Dietetics

Cite this

Metabolism of vitamin B6 by human kidney. / Zempleni, Janos; Kübler, Werner.

In: Nutrition Research, Vol. 15, No. 2, 01.01.1995, p. 187-192.

Research output: Contribution to journalArticle

Zempleni, Janos ; Kübler, Werner. / Metabolism of vitamin B6 by human kidney. In: Nutrition Research. 1995 ; Vol. 15, No. 2. pp. 187-192.
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