Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Ann Nutr Metab 2010;57:228–233 DOI: 10.1159/000321682 Giardia lamblia Infection and Its Implications for Vitamin A Liver Stores in School Children Humberto Astiazaran-Garcia   a Veronica Lopez-Teros   a Mauro E. Valencia   a Francisco Vazquez-Ortiz   a Norberto Sotelo-Cruz   b Luis Quihui-Cota   a a  Departamento de Nutrición y Metabolismo, Centro de Investigación en Alimentación y Desarrollo, A.C. y b  Hospital Infantil del Estado de Sonora, Hermosillo, México though the mean serum retinol levels did not change sig- nificantly after treatment for Giardia (p 1 0.05), the MRDR values showed significant improvement (p ! 0.002). Conclu- sion: Giardiasis not only compromises the vitamin A status through intestinal malabsorption, it also causes profound mobilization of liver retinol stores. Copyright © 2010 S. Karger AG, Basel Introduction Giardia lamblia, the causal agent of giardiasis, is the most common intestinal protozoa worldwide [1, 2]. De- spite being one of the most studied parasites, little is known about Giardia’s pathogenic mechanism, although it is reported that it involves damage to the intestinal ar- chitecture, particularly to microvilli [3, 4]. These changes correlate with compromised nutrient absorption [5, 6]. Once the infection has been cleared, the intestinal struc- ture recovers and resumes its normal activity levels. Several authors report that Giardia compromises vita- min A absorption and serum levels [7–10]. Nevertheless, Key Words Giardia lamblia infection  Retinol  Modified relative dose response Abstract Background: Vitamin A deficiency (VAD) is a nutritional problem affecting the health of people in developing coun- tries because VAD compromises innate and adaptive immu- nity, increasing a person’s predisposition toward infectious diseases. In addition, a high prevalence of infectious diseases continues to be a problem in developing countries, includ- ing Giardia lamblia. G. lamblia may be related to VAD because of its ability to change the intestinal architecture, thereby compromising the absorption of vitamin A. The aim of this study was to evaluate the effect of giardiasis on serum reti- nol levels and vitamin A liver stores in school children. Meth- ods: Thirty Giardia-infected school children participated in this study. Vitamin A liver stores were evaluated with the modified relative dose response (MRDR) technique, and an- tiparasitic treatment was administered. In addition, anthro- pometric and dietary data were collected. Results: Accord- ing to anthropometric indicators (age-appropriate Z scores for weight, height and body mass index) and daily vitamin A intake, the children had a normal nutritional status. Al- Received: January 29, 2010 Accepted after revision: October 4, 2010 Published online: December 8, 2010 Humberto Astiazaran-Garcia, PhD Departamento de Nutrición y Metabolismo, Centro de Investigación en Alimentación y Desarrollo, A.C., Carretera a la Victoria, Km 0.6 Apartado Postal 1735, Hermosillo 83000 (México) Tel./Fax: +52 662 289 2400, E-Mail hastiazaran  @  ciad.mx © 2010 S. Karger AG, Basel 0250–6807/10/0574–0228$26.00/0 Accessible online at: www.karger.com/anm F. Vazquez-Ortiz is deceased.