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.
Fresh meat contains vitamin C, as most animals can synthesize it themselves. Jerky is uncooked, just dried.
Fermentation can develop vitamin C, depending on what you’re fermenting. Cabbage is probably the most famous example, but pretty much everything you ferment produces at least a little.