EcoHealth 9, 113–121, 2012 DOI: 10.1007/s10393-012-0781-7 Original Contribution 2012 The Author(s). This article is published with open access at Springerlink.com Retinol Assessment Among Women and Children in Sahelian Mobile Pastoralists M. Bechir,1,2,3 E. Schelling,2,3 K. Kraemer,4 F. Schweigert,5 B. Bonfoh,6 L. Crump,2,3 M. Tanner,2,3 and J. Zinsstag2,3 1Centre National de Nutrition et de Technologie Alimentaire du Minist`ere de la Sant´e Publique au Tchad, BP 440, N’Djamena, Chad 2Swiss Tropical and Public Health Institute, The University of Basel, Socinstrasse 57, 4002 Basel, Switzerland 3The University of Basel, Petersplatz 1, 4003 Basel, Switzerland 4Sight and Life, P.O. Box 2116, 4002 Basel, Switzerland 5Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114–116, 14558 Bergholz-Rehbru¨cke, Germany 6Centre Suisse de Recherches Scientiﬁques en Coˆte d’Ivoire, P.O. Box 1303, Abidjan 01, Coˆte d’Ivoire Abstract: Micronutrient deﬁciencies are widespread in developing countries, particularly in remote com- munities such as mobile pastoralists. The nutritional and vitamin A status of this population is not well- documented in Chad. This study assessed serum retinol levels among women and children under ﬁve-year-old in nomadic and semi-nomadic pastoralist and rural-settled communities, who are similarly exposed to risk factors such as gastrointestinal parasitic infection, anaemia and emaciation. The novel method of portable ﬂuorometry was used for the ﬁrst time to measure b-carotene and retinol levels in a pastoral nomadic area. Moderate level blood retinol deﬁciency (<0.7 lmol/L) was observed in 5% (CI 1–11) of nomadic, 29% (CI 13–45) of semi-nomadic and 22% (CI 8–35) of sedentary women. In children, 1% (CI 0.1–4), 17% (CI 9–25) and 28% (CI 18–39), respectively, had moderate level blood retinol deﬁciency. In nomadic communities, women and children had blood retinol levels close to normal. Deﬁciency of retinol was strongly linked with lifestyle (nomadic, semi-nomadic and settled) among women and lifestyle and age among children. The results support an ecological linkage between human retinol levels and livestock milk retinol. This study shows the feasibility of portable retinol and b-carotene measurement in human blood as well as human and animal milk under remote ﬁeld conditions, but the approach requires further validation. Keywords: vitamin A, retinol, nomadic pastoralist, Chad INTRODUCTION Worldwide, 250 million school children are estimated to be vitamin A deﬁcient, and night blindness affects 5.2 million preschool aged children and 9.8 million pregnant women, (McLaren and Frigg 2002; WHO 2009). The majority of Published online: July 24, 2012 Correspondence to: J. Zinsstag, e-mail: jakob.zinsstag@unibas.ch those affected are living in the poorest regions of Africa and Asia (Maida et al. 2008). Vitamin A (VAD) and other micronutrient deﬁciencies are referred to as ‘hidden hun- ger’ (McLaren 2008). Along with iron deﬁciency, VAD ranks among the ten most important risk factors for dis- ease, causing 1.4% of mortality globally (Chacko and Sivan 2008). Estimates indicate that 50% of mortality due to measles in children under ﬁve could be prevented through