Aktuelle Neurologie 2005; 32 - M106
DOI: 10.1055/s-2005-919232

Oral treatment of vitamin B12 deficiency proven effective in subacute combined degeneration

J Wellmer 1, J Hoever 1, K.U Sturm 1, R Obeid 1, W Herrmann 1, T Klockgether 1, M Linnebank 1
  • 1Bonn, Homburg

Objective: Vitamin B12 deficiency due to malabsorption, nutritional deficiency or inborn errors of metabolism may lead to pernicious anemia, subacute combined degeneration (SCD) of the spinal cord and additional neurological symptoms. Randomized prospective studies have shown that pernicious anemia can be safely treated with oral vitamin B12, since trace amounts of oral vitamin B12 are absorbed even in complete absence of intrinsic factor. However, it is still common practice to treat SCD with intramuscular injections. We examplify oral treatment in a case of a 24-year-old female with SCD caused by vitamin B12 deficiency due to a lack of intrinsic factor in chronic lymphocytic pangastritis with marked glandular atrophy.

Methods: Before and during oral treatment with 1800µg cyanocobalamin, clinical and laboratory routine parameters were monitored as well as plasma levels of vitamin B12 and of total homocysteine and methylmalonic acid, which are sensitve markers of functional vitamin B12 deficiency.

Results: Before therapy, pernicious anemia was diagnosed showing hypersegmented polymorphonuclear neutrophils, an abnormal red blood cell count (3.6 million/ml; normal: 4.2–5.4) and an elevated mean corpuscular volume (108fl; normal: 80–96). Plasma vitamin B12 was reduced to 19pg/ml (normal: 180–920). Fasting total plasma homocysteine was 98.1µmol/l (normal: 5–10), plasma methylmalonic acid was 10,061nmol/l (normal: 70–271). After one week of treatment blood vitamin B12 levels normalized. Within a few weeks, homocysteine and methylmalonic acid levels as well as routine laboratory parameters were within the normal range, and clinical symptoms as well as signs os SCD in MRI recovered (figure A: before treatment, figure B: 10 weeks after treatment). 900µg cyanocobalamin was found to be the appropriate oral daily dosage for long-term treatment in this patient.

Conclusions: Efficacy of oral treatment in SCD has not been systematically studied, and SCD patients still receive intramuscular treatment disregarding its disadvantages and risks. The present report suggests that oral treatment of vitamin B12 deficiency may be a promising alternative to intramuscular injections in SCD patients and should be evaluated in clinical trials.