1. Department of General Internal Medicine, University Hospital Bern and University of Bern, Bern, Switzerland
2. Laboratory of Human Nutrition, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
3. Laboratory of Ion Beam Physics, ETH Zurich, Zurich, Switzerland
4. Centre on Aging and Mobility, University of Zurich and Waid City Hospital, Zurich, Switzerland
5. Geriatric Clinic, University Hospital Zurich, Zurich, Switzerland
6. Human Nutrition and Health, DSM Nutritional Products, Kaiseraugst, Switzerland
7. Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland