The Different Forms of Vitamin C

Q In reading your article on the best way to take vitamin C, a question came up. I have been told by a food biologist that ascorbic acid is not the same as vitamin C. Can you explain the difference, if any?

CHERI, Mazeppa, MN

A There is no difference—they’re identical, by the very definition of vitamin C. Perhaps what your friend was trying to say was that the term vitamin C is also used (legitimately) to encompass certain chemical derivatives of ascorbic acid that have similar vitamin C activity in our bodies. They do have different degrees of bioavailability, however.

The natural and synthetic forms of L-ascorbic acid (pure vitamin C) are chemically identical—and so, therefore, are their biological activities. Then there are the mineral ascorbates (metallic salts of ascorbic acid), which are less acidic and may thus be easier on the stomach. All these compounds are water-soluble. Finally, there are some fat-soluble forms of vitamin C, such as ascorbyl palmitate. Durk Pearson & Sandy Shaw combine calcium ascorbate with ascorbyl palmitate, which they refer to as a naturally occurring antioxidant synergist, in their formulation Double C.