When choosing a vitamin C supplement, should you look for one that is "reduced," "L" form (l-ascorbic acid), or "natural"?

Answer:

No, no, and no. None of these things matter because the "ascorbic acid" in all common vitamin C supplements is l-ascorbic acid and is in the reduced form, and you will find exactly the same form in natural vitamin C. If anyone tries to tell you otherwise, they either don’t know what they are talking about or are hoping to fool you so you'll pay more than you need to. Be sure to keep the bottle closed and out of direct light to minimize the chance of the reduced vitamin C from becoming oxidized.

We explain this in the What to Look for When Buying Vitamin C section of our Vitamin C Supplements Review, where you can also learn the facts about other forms of vitamin C and their absorption, such as "buffered" (Ester-C and sodium ascorbate) and "slow-release," liposomal vitamin C, and products with "bioflavonoids." Also see our Top Picks among vitamin C supplements based on our tests and learn about vitamin C dosage -- many people take more than is necessary, which can have negative effects.