Ester-c calcium ascorbate is a unique and patented form of vitamin c. It is made using a proprietary, water-based manufacturing process which results in a ph neutral product that contains naturally occurring vitamin c metabolites. These metabolites activate the vitamin c molecules, making it easier for the body to transport them from cell to cell for numerous health benefits. One clinical study showed that ester-c increased vitamin c levels in the body. 1 White blood cell levels of vitamin c were elevated in subjects receiving ester-c when measured after initial dose. The presence of key metabolites such as threonate may contribute to this increased level and retention of vitamin c by the cells. In one published study, individuals sensitive to acidic foods were given one gram of vitamin c as ascorbic acid or as ester-c. Subjects reported heartburn significantly more frequent and severe after intake of ascorbic acid and subjects rated ester-c as tolerated very good -- significantly more than ascorbic acid. 2 So for anyone who has difficulty tolerating vitamin c, it's comforting to know that ester-c is non-acidic and gentle on the stomach. The main benefit of ester-c is its quick absorption and retention in the immune system. Enhanced absorption with c-sorb non-acidic and stomach friendly gives you powerful immune system support gives the body antioxidant protection.