EsterC, consisting primarily of calcium ascorbate, is a natural, nonacidic water-soluble form of vitamin C that is distinguished by its unique chemical composition and biological activity. It is manufactured in an exclusive, water-based process that results in a mixture of naturally occurring vitamin C metabolites, including ascorbate, dehydroascorbate, and threonate. The bioflavonoids quercetin, rutin and pomegranate extract are powerful free radical scavengers that complement the roles of vitamin C. Quercetin helps maintain healthy histamine release and moderates healthy leukotriene and prostaglandin metabolism. Rutin and pomegranate extract provide important support for blood vessel integrity and healthy cell function.