Is vitamin b12 causes hematuria? Ive been to the doctor for my physical exam and did urinalysis, and the result said i got uti and rbc. I took amoxicillin 250mg TID for 3 days, as well as urology referral. On the urology clinic, they test my urine, he said i still got infection and rbc, so he said he will send it for culture and he will call me for the result. After 3 days he said, the culture is negative. My question is, is vitamin b12 could affect to have hematuria? I haven't seen any blood in my urine. I have vaginal delivery december 31, 2015 and my tubal ligation january 29,2016. I did not mention to the doctor that i am taking b12. But i am on lisinopril and maxzide. My blood pressure is been controlled.