比如 NutriFlair 的LVC，在Q&A里（page 3）说是：

“Question: Are any of the ingredients synthetic, not derived from natural sources?
Answer: Thank you for your question. 

All ingredients in our Liposomal Vitamin C are derived from natural sources. No synthetic ingredients were used. 

NutriFlair Seller · March 29, 2020”

https://www.amazon.com/gp/product/B07DH1ZJZ9/ref=ask_ql_qh_dp_hza