Active Immune contains high-strength Vitamin D, Vitamin C, and Zinc. It helps support a healthy immune system throughout the year. Vitamin D, often referred to as the sunshine vitamin, can be difficult to maintain, especially during the winter months. It contributes to a healthy immune system and also supports healthy bones and muscle function. Vitamin C is an antioxidant that helps protect cells, maintain normal function of blood vessels, bones, and cartilage, and supports the immune system.