المراجع. ↑ Adit Ginde, Jonathan Mansbach, Carlos Camargo (23-2-2009), "Association Between Serum 25-Hydroxyvitamin D Level and Upper Respiratory Tract Infection in the Third National Health and Nutrition Examination Survey", Archives of internal medicine, Issue 4, Folder 169, Page 384-390.Edited. ↑ Jennifer Warner (23-2-2009), "Low Vitamin …