Key Features: Nature S Bounty Immune 24 Hour + nourishes your immune system with 1000 mg of Ester-C, the only Vitamin C that provides 24-hour immune support while lasting up to two times longer than regular Vitamin C. It additionally contains Vitamin D, Vitamin A and Zinc for extra immune plus antioxidant support. Elderberry and echinacea plus 9 essential nutrients also help keep you healthy