Uses mineral ascorbates, a requirement for high dose C supplementation, is in capsule form (more absorbable), and has 1 gram per pill to reduce the number of pills one has to consume. Clearly superior! I take 2 g. C / day so this is clearly the best choice for me! Next time I am going to buy the larger bottle. Vitamin C (ascorbic acid) is not the active form, whereas mineral ascorbates are the active form. The nonactive form (ascorbic acid) is an acid and the body has to rob calcium from the diet or bones to make a mineral ascorbate before it can be used (which means bone loss). A mineral ascorbate form of C, like Ester C, is the only sensible way to take this vitamin.