Threonic Acid & Alpha Lipoic Acid EnhancedBuffered, Bioavailable Vitamin CVitamin C is best known as an antioxidant that can protect the body's cells and molecules from damage by free radicals. NOW AlphaSorb-C includes Transport C-PLUS, a trademarked combination of Threonic Acid-enhanced, buffered (non-acidic) Calcium Ascorbate with Alpha Lipoic Acid. Threonic Acid is a Vitamin C metabolite that has been shown to enhance cellular uptake of Vitamin C. Alpha Lipoic Acid functions as a free radical scavenger that can help regenerate Vitamin C in the body and may also enhance its utilization. With this unique formula, NOW has created a well-absorbed and highly biologically available Vitamin C supplement.