I take Vitamin C sometimes, especially in the winter, or when I'm feeling run down, or like I might be coming down with a cold, on the theory that it can't hurt to take some Vitamin C, and it might help.
I bought these because they are only 250 mg. Most of the Vitamin C tablets I've seen in the stores come in 500 mg or even 1000 mg dosages.
I figured that with the 250mg tablets, if I really want 500 mg worth, I can just take two, and if not, I can take one.
250 mg is 417% of the RDA, and I already get some vitamin C in the multivitamin that I take daily. So usually, I figure that's enough.
These are also very inexpensive -- they only cost a penny each. Walgreen's also puts them on sale sometimes at two for the price of one, so that brings them down to half a penny!
I usually take one in the morning if I'm feeling a bit run down or stressed out or if the weather is cold and/or damp. If I'm actually coming down with a cold, then I'll take another one.
I can't say that the Vitamin C that I take works or it doesn't, because that's not something you can tell, as an individual. (If you take a vitamin and then don't get a cold, it's not possible to tell if the reason you didn't get the cold is because you took the vitamin, or if you would not have gotten the cold even without taking the vitamin.) You need to have scientific studies that compare people who take a particular vitamin to people who don't. And, while I'm not an expert, as far as I know the scientific studies on Vitamin C are not conclusive.
But Vitamin C is a water soluble vitamin, which means that it doesn't build up in your body the way fat-soluble vitamins like Vitamin A do. In reasonable doses, it probably won't do any harm. Also, again as far as I know, there's no difference in the effectiveness between bargain-priced Vitamin C like the Walgreen's brand, and expensive Vitamin C from health-food-company brands. Anything you hear to the contrary is probably just marketing hype. So that's why I look for the lowest price.