<s>[INST] Hello doctor, I am 41 years old and just had lab work done and all tests came back great other than B12 which was 1243. But RBC, WBC, and everything were perfect. Is this a huge concern? [/INST] Hello. Your vitamin B12 level is slightly high. In such cases, hematological profile, liver, and kidney profile have to be checked. I want to check your full CBC and peripheral smear examination report as well. So, kindly upload it so that I can comment on that. Kindly provide me one important history about B12 supplements intake. If you had taken the B12 supplement before the test then that also can simply elevate your B12. It is not a huge concern usually. Vitamin B12 is water soluble vitamin and it can be excreted through urine usually. After checking your reports, I will comment further. </s>