No synthetic ingredients used.
參見視頻：
Natural Vitamins vs Synthetic vitamins
後注：但事實上，如下麵各位所說，也可以 google 到：
"You may be surprised to find out that almost all multivitamins (including Vitamin C in these multivitamins) are made using synthetics."
"Supplements that list nutrients individually, such as vitamin C, or use chemical names like ascorbic acid, are almost certainly synthetic."
我以前沒有意識到 synthetic 在這裏有雙重含義。我的理解是，所有的 Vitamins Supplements 都是 synthetic，但可能不是 sourced from synthetic ingredients，而是 natural sources，比如 sourced from non-GMO corn。但 Vitamins Supplements 本身還是 synthetic，是 synthetic vitamins。在上述視頻裏還是不被推薦長期服用的。如果我的理解有偏差，請指正。
