(OR09-04-23) Relative Validity of Reflection Spectroscopy-Measured Skin Carotenoids as a Biomarker of Dietary Carotenoid Intake in Diverse US Toddlers

Objectives: Carotenoids are fat-soluble pigments found predominantly in fruits and vegetables (FVs). Skin carotenoid concentration measurements may provide a rapid and non-invasive biomarker of toddler dietary intake. The purpose of this study is to evaluate the correlation of pressure-mediated reflection spectroscopy-measured skin carotenoid scores (SCSs) with proxy-reported carotenoid intake in diverse, US toddlers. We hypothesize that toddler carotenoid intake is a significant predictor of SCS.

Methods: A secondary analysis of a randomized controlled trial of ethnically diverse toddlers (12-36 months, 38% Hispanic/Latino, 44% non-Hispanic white, 32% Black/African American, 14% Asian) and adult guardians was conducted. Participants (n=50) recruited from Houston, TX Sept 2018 - Apr 2019 were randomized to a 10-week playgroup-based intervention or lecture-based control group focused on healthy diet, physical activity, and social/emotional parenting for toddlers. At baseline and completion, SCS was measured (Veggie Meter™, Longevity Link, Utah), toddler diet was reported by the guardian using the Kids Bites FFQ, carotenoid intake estimated using NDSR nutrient analysis software, and height and weight were measured. SCS validity as a marker of intake of total carotenoids (sum of all species) and individual carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein & zeaxanthin, and lycopene) was examined using generalized mixed linear models controlling for participant, BMI, age, study group, and study time point (pre/post). A bivariate Pearson’s correlation test evaluated the relation of change in carotenoid intake and change in SCS. Statistics were conducted in SPSS (alpha=0.05).

Results: SCSs were positively predicted by intakes of total carotenoids (p=0.006), beta-carotene (p=0.003), and lutein & zeaxanthin (p=0.015). Intakes of alpha-carotene, beta-cryptoxanthin, and lycopene did not predict SCS. There was an association between change in total carotenoid intake and change in SCS over the study (rho=0.329, P=0.019).

Conclusions: Reported dietary carotenoid intake is a significant predictor of SCSs in a diverse population of toddlers. Toddler skin carotenoid measurement holds promise as a rapid, objective, non-invasive biomarker of dietary carotenoid intake.

Funding Sources: USDA/ARS, University of Houston GEAR Grant