Instituto de Nutricao Josué de Castro;
Federal University of Rio de Janeiro;
Rio de Janeiro 21941-913;
Brazil;
Departamento de Clínica Médica;
Hospital Universitário Clementino Fraga Filho;
Federal University of Rio de Janeiro;
Rio de Janeiro 21941-901;
Brazil;
Nutrition and Immunology Chair;
ZIEL Research Center for Nutrition and Food Sciences;
Technical University of München;
Freising-Weihenstephan;
80333 München;
Germany;
Crohn's disease; Vitamin A; Serum retinol; Relative dose response test; Body composition;