Vitamin C contributes to normal collagen formation for normal cartilage function and normal skin function. It contributes to the reduction of tiredness and fatigue. Biotin contributes to the maintenance of normal hair and skin. Manganese contributes to normal connective tissue formation. Selenium contributes to the maintenance of normal hair and nails. Zinc contributes to the maintenance of normal hair, nails, and skin. Vitamin C, vitamin D, selenium, and zinc contribute to the normal function of the immune system. Vitamin C, vitamin E, manganese, selenium, and zinc contribute to the protection of cells from oxidative stress.