This document contains a lab report for a vitamin B12 test performed on a blood sample collected from Rupak Bhattacharjee, a 45-year-old male. The test result showed a vitamin B12 level of 244 pg/ml, which is within the normal reference range of 211-911 pg/ml. Vitamin B12 is important for DNA synthesis and cell maturation. Low levels can indicate neurological or blood cell abnormalities. The test was performed using a competitive chemiluminescent immunoassay method.