Assessment of Skin Carotenoid Measurement as a Means to Detect Vitamin A Deficiency in Children and Pregnant Women of Nepal

Abstract

Background: Vitamin A deficiency (VAD) is an ongoing public health concern among children and pregnant women in Nepal despite robust national efforts to screen and treat this vision- and life-threatening condition.

Objectives: This study aimed to evaluate skin carotenoid scores measured using the Veggie Meter as a rapid, noninvasive screening tool for VAD in Nepali children and pregnant women.

Methods: This comparative cross-sectional study enrolled 164 pregnant women and 168 children (aged 8 to 12 y) from public hospitals in three distinct outlying ecological regions of Nepal (Terai, Hill, and Mountain). The primary outcome assessed whether skin carotenoid status could be a biomarker for VAD. We determined skin carotenoid scores using the Veggie Meter and compared them with serum retinol and total carotenoid concentrations assessed by HPLC. Correlation analysis was used to determine bivariate associations between serum retinol and total carotenoid concentrations, and the Veggie Meter assessed skin carotenoid status. Receiver operating characteristics curves were determined, and a P value <0.05 was considered statistically significant.

Results: We found that 8.5% of pregnant women and 13.0% of children in this study had severe VAD (serum retinol < 200 ng/mL). There were significant correlations between skin carotenoid scores with serum retinol and total carotenoid concentrations among pregnant women and children (r = 0.253-0.530, P ≤ 0.001). The Veggie Meter detected severe VAD with 57.1% sensitivity and 82.7% specificity in pregnant women and 61.9% sensitivity and 75.9% specificity in children.

Conclusions: Although sensitivity and specificity were moderate for detecting VAD with the Veggie Meter, skin carotenoid assessment using this rapid, noninvasive portable device could still be valuable for high-risk VAD screening in Nepal and similar developing countries with limited access to laboratory measurement of serum vitamin A concentrations.

Keywords: Nepal; Veggie Meter; serum carotenoids; serum retinol; skin carotenoids; vitamin A.

FIGURE 1

Serum total carotenoid concentrations statistically correlated with serum retinol concentrations in pregnant women (n = 164) (A) and in children (n = 162) (B).

FIGURE 2

Serum total carotenoid concentrations statistically correlated with skin carotenoid score in pregnant women (n = 164) (A) and in children (n = 162) (B). RU, reflection units.

FIGURE 3

Serum retinol concentrations and skin carotenoids score were statistically correlated in pregnant women (n = 164) (A) and in children (n = 162) (B). RU, reflection units; VAD, vitamin A deficiency.

FIGURE 4

Receiver operating characteristic (ROC) analysis with sensitivity and specificity for vitamin A deficiency skin carotenoid cutoff score (n = 326). VAD, vitamin A deficiency.