1. Institute of Nutritional and Food Sciences-Nutritional Epidemiology; University of Bonn; Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study Center at the Research Institute of Child Nutrition Dortmund; Germany
2. Steroid Research and Mass Spectrometry Unit; Center of Child and Adolescent Medicine; Justus-Liebig-University; Giessen Germany
3. Children's Hospital; University of Cologne; Cologne Germany