You have to pick:

Surprisingly, this may actually be survivable. Though you're going to need an ICU and a new supply of vitamin C in your body *very* quickly.

Vitamin C has many functions in the human body, some of them quite important. I looked them up on Wikipedia to try to guess the results of suddenly not having any:

* It's vital for collagen synthesis enzymes. This is why people suffering from scurvy have joint problems and lose teeth. Fortunately this is a long-term issue, so as long as you get vitamin C back in your system I don't imagine this will be a noticeable problem.

* It's used when synthesizing carnitine, which is vital for ATP synthesis in mitochondria. If you lost all your carnitine you'd instantly die, but fortunately that's not what's happening here - it's just the synthesis that's being stopped. As far as I can see there isn't a high turnover of carnitine in the body, so you can probably coast for a while with your existing supply. You can even take carnitine supplements so you don't need to synthesise it, though that shouldn't be needed if you're taking a bunch of vitamin C after choosing this.

* It's used in several enzymes that human cells use to deal with low oxygen conditions. I guess don't hold your breath until you get back on the vitamin C wagon again. Maintain good circulation until then too, to make sure none of your tissues have localized oxygenation problems. This might be an issue with the next effect, though...

* It's used by an enzyme that converts dopamine to norepinephrine (aka adrenalin). This one right here is the most potentially deadly short-term problem I see. Norepinephrine is a neurotransmitter and breaks down rapidly, and it's used throughout the sympathetic nervous system to essentially stimulate your organs to perform various tasks. So if you had no norepinephrine your body would basically shut down, your various organs would be acting like their "off" switches had been hit. Worst immediate effects would probably be crashing blood pressure. Jabbing yourself with an epipen might help with your organs shutting down, but I get the impression that norepinephrine in the bloodstream is a separate signalling hormone than norepinephrine in neurons - your neurons make it themselves and recycle it from their own synapses, they may not take it up from the blood stream. So this is bad. Norepinephrine is also used in the brain itself to stimulate widespread activity, so you'll probably pass out soon.

* Peptidyl-glycine alpha-amidating monooxygenase is an enzyme that catalyzes the conversion of glycine amides to amides and glyoxylate. Uh... no idea what the implications of this one not working are. Seems to be more hormone-related stuff, which we're already suffering from thanks to the failure of norepinephrine synthesis. I'm not going to go digging deeper than Wikipedia on this one.

So, in a nutshell; you'll probably soon pass out and your organ systems will shut down. If you can get vitamin C back into you before you die you might recover fully, though. After choosing this option call 911 immediately, tell them you have extreme vitamin C deficiency and your norephineprine levels are crashing, and then take as much vitamin C supplement as you can get your hands on before you pass out. It's impossible to overdose on vitamin C. If the ICU can keep you stable long enough you could be okay.

Oh, the excess vitamin A is also bad, but not very. Hypervitaminosis A has nasty chronic effects but acute effects pass without long-term damage. This is a one-time excess dose of vitamin A, and may not even be enough to cause problems. I'm more concerned about the complete lack of vitamin C.