I am sorry for your experiences @accio. I suppose I may fall into that "arrogant" category, although not quite as you have outlined.
I used to take a multivitamin Daily, religiously, along with Calcium/Vit D³, until in chatting with my PSYCHIATRIST of all people (he really is the VA pill pusher) he commented that: "Americans have the most Vitamin Rich Urine in the world" meaning of course, that many of us DO get most if not all what we need in our diet, and what our bodies don't need, we just pee it out.
Vit D and C are not stored by the body, and I almost never spend enough time in the sun to count, but I HAVE started drinking more milk, so I dropped the Calcium and am just taking Cholecalciferol (Vit D³).
Curiously about 6 months ago a blood test came back showing I was SERIOUSLY deficient in B¹² so I now have that prescribed and I take it daily.
I have a (rather old) bottle of 1000Mg Vit C, but I also try to keep Real Grapefruit and eat at least one per day.
I don't understand the toilet paper obsession; if things get that bad, with people not going to work and dropping dead in the streets, the city water supplies will stop, and you'll have plenty of butt wipe (I don't mean you personally) but no water to flush with.
When I see that madness on the boob tube, I just shake my head.
btw. I am 65, with COPD so I am very much "at risk" as well.
Be strong my friend.