Extra C 950mg, 90 capsulesExtra C contains a high potency, patented form of vitamin C, which delivers enhanced absorption and retention. In this clinically researched formulation, the addition of lipid metabolites enhances the bioavailability of vitamin C, meaning that it can be more rapidly absorbed and subsequently retained by the human body than other traditional forms. (It has been naturally derived from corn with the addition of fatty acids to enhance bioavailability).