Authorized Vendor for C-500. Vitamin C is perhaps the most popular vitamin known to man. It is consumed in a supplemental form by millions of people across the world for its antioxidant properties, which are well-documented in medical research. C-500 provides a potent dosage of this key vitamin and is blended with Bioflavonoids, Acerola, Rose Hips and Rutin, which are natural synergists to Vitamin C.*.