Thursday, 17 May 2012

Spurious Elevations of Vitamin B12 with Pernicious Anemia

Yang DT, Cook RJ. Spurious elevations of vitamin B12 with pernicious anemia. N Engl J Med. 2012 May 3;366(18):1742-3.

Level 2

Have you ever seen a patient with pernicious anemia with spuriously elevated levels of vB12? 

This report of 2 cases, of pernicious anaemia, highlights an important the problem of false normal results for vitamin B12 levels generated by automated analysers when the serum of patients with pernicious anaemia are evaluated. The results have been attributed to high levels of intrinsic factor–blocking antibodies that interfere with the assay.

Subacute combined degeneration of the spinal cord due to vB12 deficiency.
Teaching point: If you have a high-index of suspicion that a patient has vB12 deficiency please check plasma levels of homocysteine and methylmalonic acid and screen the serum for anti-intrinsic factor–blocking antibodies and antiparietal-cell antibodies. Or you can do the methionine loading test. 

Smooth red tongue due to vB12 deficiency 


  1. Anemia is a condition where there is a lower than normal number of red blood cells in the blood, usually measured by a decrease in the amount of hemoglobin.

    Critical illness cover

  2. good blog :) here's more info on anemia if required