Is b12 deficiency common in Ulcerative Colitis?

I wouldn't say b-12 deficiency is common in ulcerative colitis patients, but it can happen. Do you have pancolitis with ileum backwash? As b-12 is absorbed within the ileum.

"Should supplemental vitamins be taken? If so, which ones?
Again, that depends on the extent and location of the disease. Vitamin B-12 is absorbed in the lower ileum—that means that people who have ileitis (Crohn's disease that affects the ileum) or those who have undergone small bowel surgery may have a vitamin B-12 deficiency because they are unable to absorb enough of this vitamin from their diet or from oral supplements. " www.ccfa.org/resources/nutrition-and-ibd.html

I have a B12 deficiency, it was detected through a routine blood test. My symptoms were shaking/tingling hands, I didn't put it down to b12 at the time as I thought it was part of my major flare. My scores were quite low at 100, I was given injections every other day for 2 weeks, now every 3 months for maintenance. I've been told I need to keep having the injections for the next 2/3 years, then I can try supplements.
I don't believe it's common in UC patients.