You know, sailors used to get scurvy because of C deficiency back a couple centuries ago. Vitamin C degrades really easily, but is there any way you can store it long term other than pills or tablets? I’m just wondering if it would have been possible to do this in the past with the technology that was available.
I’m kind of surprised no one has said honey. While I can’t find exactly when honey was first used as a preservative, it’s believed that it was first used in ancient Egypt. I also don’t know if vitamin C specifically was ever preserved in honey but honey has been used as a preservative for fruit.