It might be worth giving plain l-ascorbic acid powder in water a shot, since it's a lot cheaper than liposomal, and doesn't have the fillers that tablets have.
Small doses throughout the day if it can be arranged.
If not a vegetarian, one can get zinc from muscle meat, and balancing copper from liver. About 7 oz per week of lamb's liver covers the RDA. Beef liver is about twice that.
Liver is fairly rich in potassium and vitamin A as well.