What is Optimal Vitamin C Powder derived from? Ceylon Keeslar April 11, 2017 21:51 Updated Follow The vitamin C is from corn. The sources of quercetin, rutin and hesperidin are unknown. Stay tuned! Related articles Does Optimal Vitamin C Powder contain corn or grain-derived ingredients? Does Optimal Liposomal Vitamin C contain GMO ingredients? What is Optimal Vitamin D Drops derived from? What is L-Lysine derived from? Comments 0 comments Article is closed for comments.