Vitamin C is best known as an antioxidant that can maintain cellular health by neutralizing 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.* Transport C-PLUS® is a registered trademark of Helios Corp. Natural color variation may occur in this product.