Vitamin B-12 Associated Neurological Diseases Medication

Updated: Oct 22, 2018
  • Author: Niranjan N Singh, MBBS, MD, DM, FAHS, FAANEM; Chief Editor: Selim R Benbadis, MD  more...
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Medication Summary

Standard treatment in patients with vitamin B-12 deficiency consists of parenteral or oral cobalamin. The hematologic abnormalities may respond to folate, but the neurologic manifestations only respond to cobalamin.

Numerous treatment regimens have been proposed, including cobalamin 1000 mcg IM/SC daily for 5 days followed by 1000 mcg/wk for 5 weeks, then 100-1000 mcg/mo for life.

Because 1% of cobalamin is absorbed by passive diffusion, administration of large oral doses is an alternative; 1000 mcg daily yields a daily absorption of 10 mcg, which exceeds the 2-mcg recommended daily allowance (RDA) requirement.

In addition to cobalamin replacement, oral IF supplementation is being evaluated. Supplementation with SAM or methionine-rich diets are being studied for N 2 O-induced myeloneuropathies.

Diagnosis and treatment of tapeworm infection and celiac and Crohn diseases can improve intestinal vitamin B-12 malabsorption. With blind loop syndrome, tetracycline can normalize the intestinal flora and vitamin B-12 absorption.


Dietary supplements

Class Summary

Cyanocobalamin is used to replenish the deficiency caused by any of the etiologies described.

Cyanocobalamin (Berubigen, Cyanoject)

Most stable and available form of vitamin B-12. Absorbed rapidly to the organism from IM or SC applications.

Oral cyanocobalamin can replace parenteral formulations. Is effective in PA because 1% of free cobalamin is absorbed via diffusion rather than requiring the presence of IF.

Folic acid (Folvite)

Folate supplementation can reverse the hematologic abnormalities, but the neurologic manifestations only respond to cobalamin.