Ester-C® Plus capsules contain a non-acidic, calcium ascorbate form of vitamin C combined with potent antioxidants to support the healthy functioning of the entire body. Ester-C® is a unique form of vitamin C that is created through a patented, water-based process that combines vitamin C and calcium. Ester-C is non-acidic and should be well-tolerated by those who are sensitive to the acidic nature of ascorbic acid.