3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold collected from decades of research studies 3 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold 2 Vitamin C for preventing and treating the common cold 3 Vitamin C for preventing and treating the common cold