1. University of Copenhagen; Faculty of Health and Medical Sciences; Blegdamsvej 3B Copenhagen N Denmark 2200
2. University Hospital Zurich and University of Zurich; Institute for Complementary and Integrative Medicine; Sonneggstrasse 6 Zurich Beijing Switzerland 8006
3. Institute of General Practice, Medical Faculty of the Heinrich-Heine-University Düsseldorf; Cochrane Metabolic and Endocrine Disorders Group; Moorenstr. 5 Düsseldorf Germany 40225