B vitamins help prevent infections and support brain function, cell metabolism, energy levels, and a healthy appetite. Vitamin C is a powerful antioxidant that contributes to the proper function of the immune system and blood vessels. Its intake results in the production of collagen. Vitamin E plays an important role in immune function, gene expression and helps keep blood vessels healthy. Vitamin D3 helps the body with the absorption and use of calcium. It is necessary for the immune and neuromuscular system and maintains the health of teeth, bones and muscles. Ginger can help aid digestion, reduce nausea and inflammation, and fight the flu.