High plasmatic concentration of vitamin B12: an indicator of hepatic diseases or tumors

To identify the diseases that are associated with a high plasma concentration of vitamin B12 and to measure the strength of this association. Retrospective study including all admissions between 1st May, 2005 and 30th April, 2008 in the UMAG pole departments (emergency, internal medicine, acute geriatrics and medical intensive care) with a test for plasma vitamin B12. The association between each of medical information system codes (solid tumors, malignant hematologic process, and renal disease) and a high or low vitamin B12 concentration was measured by odds ratios (OR) from logistic models taking into account repeated admissions, with adjustment for age and the weighted Charlson index. Among 3702 admissions, 12% had a B12 more than 820pg/ml, 10.4% a B12 less than 180pg/ml and 77.6% a normal B12 concentration. After adjustment for age and the weighted Charlson index, high concentration of vitamin B12 was associated with interstitial renal diseases (OR 2.7; 95% CI: [1.7-4.2]), and cirrhosis or hepatitis (OR 4.3; [2.9-6.4]). After additional adjustment for these parameters, it was still associated with tumors (OR 1.8; [1.2-2.6]), malignant hematologic diseases (OR 2.1; [1.3-3.5]), metastasis (OR 2.9; [1.5-5.9]), liver metastasis (OR 6.2; [2.7-14.5]), liver carcinoma (LC) (OR 3.3; [1.1-10.4]), liver tumors other than LC (OR 4.7; [1.2-17.9]) and lymphoma (OR 3.2; [1.6-6.4]) but not with myeloma (OR 1.9; [0.6-1.4]). Low concentration of B12 was associated with myeloma (OR 2.9; [1.3-6.6]). Finding a high plasma concentration of vitamin B12 should lead to a systematic search for a hepatic disease or a tumor, and particularly for a hepatic localization of a tumor.