Urinary markers in nutritional studies

Abstract

To date, the assessment of dietary intake is primarily based on self-reported data. However, it is widely acknowledged that all self-reported methods are subject to various errors. It is thus essential to minimize these errors to reduce the distortions where studies have investigated the relationships between diet and disease. Biomarkers can resolve this especially those relating to body fluids, such as saliva, blood, and urine. However, currently there are only a few biomarkers which reflect the dietary intake of specific component and/or habitual intake. This review illustrates recent development in the discovery and application of potential urinary biomarkers. Urine is selected as it is collected with ease and can be equated in terms of daily out or with reference to lean tissue via determination of urinary creatinine. The use of urinary markers include, for example, methylmalonic acid for vitamin B12 intake, menadione for vitamin K intake, hippuric acid for fruit and vegetable intake, and 1-methylhistidine for oily fish intake.