Man-made vitamins don't work near as well as their natural counterparts, just FYI.
Whichever vitamin you choose to take, be sure to crush it up so you don't wind up crapping out the amount your body won't absorb, and take it with food. One or two slices of bread are major catalysts in helping digest.
Raw spinach is a good source of Vitamin C as well as many others. It's called a superfood, but notice that it only has 14% DV of ascorbic acid in it. Compared to the man-made vitamin, this is totally the opposite. How could it be a good source then?
1. It's natural
2. It's more likely to be absorbed into the body