Vitamin C in Emergen-C may not prevent colds, but could reduce symptom severity. Excess vitamin C can cause side effects like stomach cramps and diarrhea. Emergen-C contains other vitamins that may ...

Emergen-C may help reduce the length of a cold when taken in large doses. Vitamin C supports the immune system and helps fight off bacteria and viruses. Some nutrients in Emergen-C, like zinc and B ...