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UBC Theses and Dissertations

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UBC Theses and Dissertations

Biochemical riboflavin status and its predictors in adult women aged 51-70 years in Metro Vancouver Zubair, Mohammad Saroar

Abstract

Background: Riboflavin, or vitamin B-2, functions as a coenzyme in numerous metabolic pathways and is essential for adequate cell growth. Riboflavin status has been shown to be inversely associated with the risk of cardiovascular diseases and cancers. Erythrocyte glutathione reductase activation coefficient (EGRac) is a functional indicator and considered as the ‘gold standard’ biomarker of riboflavin status. Previous studies have reported a high prevalence of biochemical riboflavin deficiency but a low prevalence of dietary inadequacy in adults aged ≥65 years. In Canada, 3% of adult women aged 51-70 years had inadequate dietary riboflavin intake; however, data are lacking on biochemical riboflavin status. Objectives: The objectives of this research were to determine the biochemical riboflavin status, and to identify the dietary, demographic and lifestyle predictors of riboflavin status in adult women (aged 51-70 years) in Metro Vancouver. Methods: This secondary analysis used data and biospecimens from a cross-sectional study of a convenience sample of 223 adult women age 51-70 years. A fasting blood sample, blood pressure measurements, sociodemographic, anthropometric and dietary intake data were collected during a single-day study visit. Riboflavin status was measured using EGRac. Plasma riboflavin concentration was analyzed using an in-house validated liquid chromatography-tandem mass spectrometry assay. Results: Overall, 29% of the study population had riboflavin deficiency (EGRac ≥1.4) and 22% had suboptimal status (EGRac ≥1.3 and <1.4). However, only 4.7% did not meet their dietary riboflavin requirements (i.e. riboflavin intake ≥0.9 mg/day). Riboflavin intake from food and supplements was significantly correlated with EGRac (Spearman-rho=-0.55; p<0.001), and plasma riboflavin concentration (Spearman-rho=0.45; p <0.001). Total riboflavin intake and Chinese ethnicity were significant predictors of biochemical riboflavin status. Conclusion: This study is the first to determine biochemical riboflavin status of free-living adult women aged 51-70 years in Metro Vancouver and Canada. It provides new information and preliminary data for future research including information on possible predictors of riboflavin deficiency in this population group. High prevalence of biochemical riboflavin deficiency and suboptimal status among the study population may be a cause for concern. The discrepancy between the diagnosis of biochemical riboflavin deficiency and total riboflavin intake inadequacy warrants more research.

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Attribution-NonCommercial-NoDerivatives 4.0 International