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? What is the breakdown of the Vitamin C in Optimal Vitamin C Powder? What is the expiration date of Optimal Vitamin C Powder? What are the ingredients in Optimal Liposomal Vitamin C derived from? What is the purpose of the "Other Ingredients" in the Histamine Block? Comments 0 comments Article is closed for comments.