What is the verdict on folic acid for ulcerative colitis patients? does the science show that uc patients should supplement it, and if yes, what dose?

Good question: The data certainly points to an association between low folate (folic acid) levels and incidence of UC. Furthermore, folate (folic acid) is protective against the development of colon cancer. Checking levels is a good idea and a gastroenterologist, especially one that specializes in IBD can guide you further. I think you are on the right track in your line of questioning. Good luck.