A few years ago Emanuel Hunt, Jr., then National Director of Midnight Basketball League, gave me a vitamin C-and-sugar recipe he still uses that his mama used to dose her large brood of young'uns with whenever they got colds. I tried it a couple of times myself, and I can attest to its effectiveness, but it takes so much more planning and work than just grabbing hot water, sugar and vitamin pills, as with the doctor-cum-trucker's vitamin C recipe detailed above. Still, some people prefer this one, and they can't screw up the directions the way so many manage to do with the other one, so I'll pass along the recipe here.
You'll need chopped onion, sugar and a jar with a good tight lid that's large enough to hold the onion with quite a bit of room to spare. Put the chopped onion in the jar and gradually add sugar, turning the jar to coat the onion pieces with the sugar. You can probably see when you've got enough sugar; there's no rule here. In a short time, you'll see juice begin to accumulate at the bottom of the jar as the sugar leaches it out of the onion. Now, seal the lid on the jar and set it on the counter overnight.
By the next day, you'll have more juice than onion, and this is your cold "medicine." Onions are the best source of vitamin C in our diet, and sugar-leached onion juice provides even more elements than my vitamin C and sugar-water recipe, except for the heat from the water to speed the sugar's fermentation action through your system (as explained above). If you're using the onion juice to stop a cold dead in its tracks, keep a jar of it on hand in the fridge and at the first sign of a cold, dose yourself with a couple of teaspoons of juice every four hours. Don't worry, it tastes delicious in an odd sort of way, and most colds will disappear within a day or so.
A batch will keep fresh in the refrigerator for days, but probably no more than a week or so. The vitamin potency does begin to dissipate within a few days, so if this recipe is your preferred viral "poison," you'll have to keep making a fresh supply so you'll have it on hand throughout the cold and flu season.