Project Details

Skin Carotenoids Assessment to Detect Vitamin A Deficiency in Children and Pregnant Women in Nepal

Raba Thapa, MD, PhD

Summary

BACKGROUND: Vitamin A deficiency (VAD) is an ongoing public health concern among children and pregnant women of Nepal despite robust national efforts to screen and treat this vision- and life-threatening condition. We conducted a comparative, cross-sectional study to evaluate skin carotenoid measurement as a rapid, non-invasive screening tool for VAD in Nepali children and pregnant women. GAP: There are no facilities for objective measurement of vitamin A deficiency in Nepal. Serum retinol analysis is very expensive and has to be sent abroad, and we have to wait a long time for the results. HYPOTHESIS: Measurement of skin carotenoids using the Veggie Meter will be a simple and non-invasive procedure for rapid screening for VAD in children and pregnant women in high-risk regions of Nepal. METHODS: In first study, we enrolled 162 pregnant women and 164 children (8 to 12 years old) from three public hospitals at three ecological regions (Mountain, Hill and Terai) of Nepal in this study. Skin carotenoid levels were assessed using the Veggie Meter® (Longevity Link Corporation, Salt Lake City, Utah, USA). The primary outcome was whether skin carotenoid measurement can successfully identify subjects with VAD. Detailed eye evaluations were conducted in subjects with low skin carotenoid scores and those with night blindness. Serum retinol and serum carotenoid levels were measured using high performance liquid chromatography technique (HPLC). Intra-class correlation coefficients were calculated. P values were considered significant if less than 0.05. In second study, a total of 324 school children between 3 to 7 years old from six schools were enrolled. Skin carotenoid levels were assessed using the Veggie Meter® (Longevity Link Corporation, Salt Lake City, Utah, USA). The skin carotenoid score was considered low when the skin carotenoid was less than 150 Reflection Units (RU). Detailed eye evaluations were conducted in subjects with low skin carotenoid scores (<150 RU) and or those with a history of night blindness. RESULTS: In first study, a total of 8.6% of pregnant women and 12.8% of children were VAD (serum retinol <200 ng/ml) even though only four had present or past ocular clinical signs of VAD. There was significant correlation of total skin carotenoids with serum retinol among the pregnant women (r= 0.255, p= 0.001) and children (r=0.253, p=0.001). There was significant correlation of skin carotenoids with serum carotenoids among the pregnant women (r=0.314, p <0.001) and children (r=0.510, p < 0.001). There was significant correlation of total serum carotenoids with serum retinol among the pregnant women (r= 0.447, p= 0.001) and children (r=0.530, p<0.001). At skin carotenoid 146 RU of veggie meter, sensitivity and specificity for detecting severe VAD were 57% and 82.4% respectively in pregnant women and 61.9% and 76.2% respectively among children. 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. A total of 324 school children were enrolled in the study. Mean age of children was 5.12 ±1.33 years. The mean skin carotenoid score was 163 RU ±71, ranging from 1 to 363 RU. The skin carotenoid level was < 150 RU in 46.9% of children, between 150 and 200 RU in 23.5% of children, and >200 RU in 29.6% of children. The prevalence of skin carotenoid scores less than 150 RU ranged from 9.8% to 74.1% in various schools. Low skin carotenoid scores (<150 RU) were found in 17% of 3 year olds, 28.3% each of 4 and 5 year olds, 20.4% of 6 year olds, and 11.2% of 7 year olds. In multivariate analysis, age was significantly associated (p=0.003; OR; 2.02; 95% CI: 1.28- 3.19) with low skin carotenoid scores. Odds of having <150 RU was 2.02 times more among the children up to five years old as compared to those over five years of age. CONCLUSION: Although sensitivity and specificity were moderate for detecting VAD with the Veggie Meter, skin carotenoid assessment using this rapid noninvasive portable device could still have immense value as a biomarker for high-risk VAD screening in Nepal and similar developing countries with limited access to laboratory measurement of serum vitamin A levels. Nearly half of the school children had low skin carotenoid scores. Skin carotenoid score was significantly lower among the lower age group. These findings emphasize the need to enhance awareness to consume plenty of green leafy vegetables and fruits in the diet. Continued vitamin A supplementation especially children up to five years may help for the growing need of children to combat vitamin A deficiency in the hill region of Nepal. IMPACT: High-risk cases for VAD can be identified immediately using a non-invasive simple portable device known as the Veggie Meter. This will facilitate prompt treatment and monitoring of dietary or supplement interventions.

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