ABSTRACT
The incorporation of objective intake measures, usually referred to as intake biomarkers, into the nutritional epidemiology research agenda has potential for a fresh and penetrating study of a broad range of dietary intake associations with subsequent chronic disease risk. Both the plausibility of the classical measurement error model and the efficiency of disease association estimates will be enhanced if the biomarker measurement error variance is small relative to that for the targeted dietary variable. The use of biomarkers in nutritional epidemiology, either directly through application to stored biospecimens from cases and controls nested within cohort studies, or indirectly through the calibration of self-report assessments using biomarker substudies, provides a major future research pathway for strengthening nutritional epidemiology research. Established nutritional biomarkers mainly derive from the recovery in urine of metabolites resulting from nutrient utilization. Human feeding studies provide the natural context for the development of novel biomarkers for nutrients or foods.
