Vitamin D Deficiency

• Department of Internal Medicine, LKH Hoergas — Gratwein, Styria, Austria
• Department of Internal Medicine, Medical University of Graz — Graz, Styria, Austria

• Hvidovre University Hospital — Hvidovre, Denmark

• Open Medicine Institute — Mountain View, California, United States

Not specified

• Creighton University — Omaha, Nebraska, United States

• Genesys East Flint Campus Clinic — Flint, Michigan, United States

• Hospital de Clínicas de Porto Alegre — Porto Alegre, Rio Grande do Sul, Brazil

• Jewish Home — San Francisco, California, United States

• Clinical Nutrition Center Naturalpha (CNCN) — Lille, France

• Department of Nutrition, Exercise and Sports — Copenhagen, Frederiksberg, Denmark