Changes of glucose metabolism and skin-collagen neogenesis in vitamin B6 deficiency

Biofactors. 2005;23(2):59-67. doi: 10.1002/biof.5520230201.


The mechanism of pellagrous changes in skin caused by a deficiency of vitamin B6 was studied in respect to neogenesis of proline in skin collagen and glucose metabolism. In vitamin B6 deficiency the insulin/glucagon coefficient in serum decreased significantly from 3.02 to 2.32, indicating a metabolic change towards gluconeogenesis. A deficiency of vitamin B6 caused a decrease in the levels of vitamin B6-dependent enzymes, such as ornithine aminotransferase, alanine aminotransferase, and aspartate aminotransferase, which also contribute to gluconeogenesis. Because the conversion of ornithine to proline via pyrroline-5-carboxylate was suppressed due to the decrease in ornithine aminotransferase activity, the amount of proline in the skin collagen fraction also decreased significantly in vitamin B6-deficient rats compared with the pair-fed control. These results suggest that the pellagrous lesions in vitamin B6-deficiency are caused by an impaired synthesis of proline from ornithine, which results in the suppression of collagen neogenesis in the skin.

MeSH terms

  • Animals
  • Blood Glucose / metabolism
  • Blood Urea Nitrogen
  • Caseins / administration & dosage
  • Cholesterol / blood
  • Collagen Type I / biosynthesis*
  • Collagen Type I / chemistry
  • Dietary Proteins / administration & dosage
  • Glucagon / blood
  • Glucose / metabolism*
  • Glucose-6-Phosphatase / metabolism
  • Insulin / blood
  • Kidney / enzymology
  • Liver / enzymology
  • Male
  • Proline / analysis
  • Rats
  • Rats, Wistar
  • Skin / metabolism*
  • Triglycerides / blood
  • Vitamin B 6 Deficiency / metabolism*


  • Blood Glucose
  • Caseins
  • Collagen Type I
  • Dietary Proteins
  • Insulin
  • Triglycerides
  • Glucagon
  • Cholesterol
  • Proline
  • Glucose-6-Phosphatase
  • Glucose