Approaches to assess vitamin a status in settings of inflammation: Biomarkers reflecting inflammation and nutritional determinants of anemia (BRINDA) project

• Type of Material: Article
• Authors: Leila M. Larson, The University of Melbourne; Junjie Guo, Emory University; Anne M. Williams, Centers for Disease Control and Prevention; Melissa Fox Young, Emory University; Sanober Ismaily, Emory University; O Yaw Addo, Emory University; David Thurnham, Ulster University; Sherry A. Tanumihardjo, University of Wisconsin-Madison; Parminder S Suchdev, Emory University; Christine A. Northrop-Clewes, Independent Public Health Nutrition Consultant
• Language: English
• Date: 2018-08-16
• Publisher: MDPI
• Publication Version: Final Published Version
• Copyright Statement: © 2018 by the authors. Licensee MDPI, Basel, Switzerland.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/nu10081100
• Title of Journal or Parent Work: Nutrients
• ISSN: 2072-6643
• Volume: 10
• Issue: 8
• Grant/Funding Information: This research was funded by the Bill & Melinda Gates Foundation and the CDC.
• Keywords: retinol binding protein; inflammation; retinol; Vitamin A; infection
• Research Categories: Health Sciences, Public Health; Health Sciences, Medicine and Surgery

Abstract

The accurate estimation of vitamin A deficiency (VAD) is critical to informing programmatic and policy decisions that could have important public health implications. However, serum retinol and retinol binding protein (RBP) concentrations, two biomarkers often used to estimate VAD, are temporarily altered during the acute phase response, potentially overestimating the prevalence of VAD in populations with high levels of inflammation. In 22 nationally-representative surveys, we examined (1) the association between C-reactive protein (CRP) or α1-acid glycoprotein (AGP) and retinol or RBP, and (2) how different adjustment approaches for correcting for inflammation compare with one another. In preschool age children (PSC) and school age children (SAC), the association between inflammation and retinol and RBP was largely statistically significant; using the regression approach, adjustments for inflammation decreased the estimated prevalence of VAD compared to unadjusted VAD (range: −22.1 to −6.0 percentage points). In non-pregnant women of reproductive age (WRA), the association between inflammation and vitamin A biomarkers was inconsistent, precluding adjustments for inflammation. The burden of VAD can be overestimated if inflammation is not accounted for, and the regression approach provides a method for adjusting retinol and RBP for inflammation across the full range of concentrations in PSC and SAC.