Validating Resonance Raman Spectroscopy: a Non-invasive Assessment of Skin Carotenoids as a Biomarker of Fruit and Vegetable Intake in Children

Background: Adult studies have found a strong correlation between serum carotenoids and skin carotenoids measured by resonance Raman spectroscopy (RRS). No published studies have examined correlations between skin and serum carotenoids among children. Objectives: (1) To validate skin RRS methodology against serum carotenoid measurements by high-performance liquid chromatography and (2) to determine if RRS skin carotenoids can be used as a valid biomarker of total fruit and vegetable (FV) intake among children. Design: Participants were 45 healthy children age 5-17 who provided 3 blood samples used to assess serum carotenoid concentrations and 3 RRS skin measurements (using a Biophotonic ScannerTM) within a 4 week period. Dietary intake of FV was assessed 3 times within 4 weeks using a 27 item food frequency questionnaires (FFQ) and the ASA24TM-Kids, an automated multiple-pass 24-hour recall (24HDR). Estimates of intake from three FFQ, completed at least 7 days apart, were averaged. Estimates of intake from 24HDR were collected on 2 weekdays and a weekend day and averaged. Results: Levels of skin and serum carotenoids were highly correlated (R2=.63,