Some websites claim that synthetic vitamin C in supplements may be a combination the active "L" form and the inactive "D" form of ascorbic acid. Is that true? Should I be concerned?
While it is true that only L-ascorbic acid (or L-ascorbate) is active, modern processes for manufacturing vitamin C for supplements produces only this form. So you would not get the "D" form from a supplement. For more information about vitamin C, including our tests and comparisons of supplements, see the Vitamin C Supplements Review >>