Riboflavin is an important determinant of vitamin B-6 status in healthy adults

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)
21 Downloads (Pure)


Background: Riboflavin is required to generate the active form of vitamin B-6 (pyridoxal 5-phosphate; PLP) in tissues, but the relevance of this metabolic interaction for nutritional status of vitamin B-6 is unclear because riboflavin biomarkers are rarely measured in human studies. Objectives: The purpose of this study was to identify the determinants of biomarkers of vitamin B-6 and riboflavin status and to examine the relationship between these nutrients in healthy adults. Methods: Multiple linear regression was performed on observational data in 407 healthy adults aged 18–92 y who did not use B-vitamin supplements. Vitamin B-6 status was assessed by plasma PLP concentrations and erythrocyte glutathione reductase activation coefficient (EGRac) was used as a functional indicator of riboflavin status. Results: Dietary intakes of vitamin B-6 and riboflavin were below the average requirements in 10% and 29% of participants, respectively. Suboptimal status of vitamin B-6 (PLP ≤30.0 nmol/L) was more prevalent in adults aged ≥60 y than in younger participants (i.e., 14% compared with 5%), whereas a high proportion (i.e., overall 37%) of both age groups had deficient riboflavin status (EGRac ≥1.40). In multiple regression analysis, EGRac (P = 0.019) was a significant determinant of plasma PLP, along with dietary vitamin B-6 intake (P = 0.003), age (P < 0.001), BMI (kg/m 2) (P = 0.031), and methylenetetrahydrofolate reductase gene (MTHFR) genotype (P < 0.001). Significant determinants of EGRac were dietary riboflavin intake (P < 0.001), age (P < 0.001) and MTHFR genotype (P = 0.020). Plasma PLP showed a stepwise decrease across riboflavin status categories from optimal (EGRac ≤1.26) to low (EGRac 1.27–1.39) to deficient status (P = 0.001), independent of dietary vitamin B-6 intake. Conclusions: The findings are consistent with the known metabolic dependency of vitamin B-6 on riboflavin status and indicate that riboflavin may be the limiting nutrient, particularly in older people, for maintaining adequate vitamin B-6 status. J Nutr 2020;150:2699–2706.

Original languageEnglish
Pages (from-to)2699-2706
Number of pages8
JournalThe Journal of nutrition
Issue number10
Early online date17 Aug 2020
Publication statusPublished (in print/issue) - 1 Oct 2020

Bibliographical note

Publisher Copyright:
Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.

Copyright 2020 Elsevier B.V., All rights reserved.


  • vitamin B6
  • riboflavin
  • biomarkers
  • dietary intakes
  • healthy adults


Dive into the research topics of 'Riboflavin is an important determinant of vitamin B-6 status in healthy adults'. Together they form a unique fingerprint.

Cite this