Immune Support Day is a proprietary formula of nutrients designed to support your health. Vitamin C and Zinc are included in the formula to support respiratory health as well as promote a healthy immune system. Elderberry is added to aid immune health. Taxifolin (BC-DHQ™) is an antioxidant flavonoid that helps fight free radicals and combat oxidative stress. Immune cells are vulnerable to oxidative stress because of the fat that they have in their membrane. High amounts of oxidative stress over time may be detrimental to the immune system.*