Background and objectives

Optically-assessed skin carotenoid status offers an objective measure of vegetable and fruit intake. Data from the Sodium and Potassium Intake (SNaK+) study was used to explore asso-ciations of carotenoid reflection scores with body size, annual household income, vegetable and fruit intake and potassium intake, and the relationship between carotenoid reflection score and 24-h urinary potassium in children.

Methods and study design

Seventy-five children (29 girls, 37 boys; 9 not stated) aged 8 to 13 years from five New Zealand primary schools were supported by the parents/caregivers to complete validated questions about their frequency of vegetable and fruit intake. Carotenoid reflection scores were measured using reflection spectroscopy and 24-h urine samples (n = 69) were collected. Differences by gender and age were tested using two-sample t-tests. Linear regression identified determinants of carotenoid reflection score.

Results

Children's overall mean (standard deviation) carotenoid reflection score was 236 (91), with 51% having low scores (< 250). Younger boys (< 10 years) had higher carotenoid reflection scores than younger girls (mean difference (95% confidence interval); 74 (4, 144). Few (8%, n = 6) children met vegetable intake recommendations. Annual household income and fruit servings per day were predictive correlates of carote-noid reflection scores (R2 = 0.17, F(2.52) = 6.10, p <0.01). Twenty-four-hour urinary potassium did not correlate with carotenoid reflection score.

Conclusions

This study identified low household income and low fruit intake as drivers of low carotenoid status in children, emphasizing the need for targeted dietary interventions. A study is required to further explore the relationship between carotenoid reflection score and potassium excretion.