Had upper gi endoscopy recently, have gastritis and only on bland boiled vegetables diet. will taking vitamin c tablets help me heal faster?

A lot faster with Rx: Unless there are other inciting risks to inflammation in your stomach (like h.Pylori, tobacco, too liberal alcohol, Aspirin or other nsaid's, etc.) your gastropathy will likely heal within a few weeks. Of course, you can speed up the healing process by starting an acid blocker drug like Prilosec otc daily. Vitamin c and boiled vegetables is not the answer.