A comparative study of total vitamin B12 and active B12 (holotranscobalamin) in patients with chronic kidney disease

Vitamin B12 deficiency is a serious disorder that can lead to severe neurological symptoms, especially if not detected and treated effectively. Nutritional deficiency due to dietary restrictions, deranged metabolism, and subsequent vitamin loss during dialysis are important causes of vitamin B12 deficiency in CKD patients. Hyperhomocysteinemia, a complication of vitamin B12 deficiency, has grown as an important risk factor for cardiovascular disease and the leading cause of mortality in patients with CKD. Serum samples were randomly selected from 124 patients (46 females, 78 males; age range 18-65 years) referred to the Dept. of Biochemistry, Institute of Nephrourology, Bangalore, India for the assessment of vitamin B12 status. For each patient, serum total vitamin B12 level and active B12 (holoTC) level were determined by chemiluminescent microparticle immunoassay on Architect ci1000 analyzer. Out of the total 124 patients, 17 CKD patients were excluded from the study, and in the remaining 107 patients, 13.08% showed a deficiency of both Total vitamin B12 and Active B12. In the 107 patients, the mean total vitamin B12 level was 604.85 ± 495.2 pg/mL, and the mean Active B12 level (holoTC) was 67.1 ± 32.75 pmol/L, with a strong positive correlation (=0.501, <0.01) between total B12 and active B12 levels. A significant deficient level of B12 was found in the patients on hemodialysis for more than three years. : Active B12 can aid vitamin B12 measurements for diagnosis of B12 deficiency and can be a potential indicator of B12 deficiency in patients with CKD.