Treatment of Deficiency Anemias

Vitamin B12 Deficiency Treatment

For vitamin B12 deficiency with neurological involvement, administer hydroxocobalamin 1 mg intramuscularly on alternate days until there is no further improvement, then transition to maintenance with hydroxocobalamin 1 mg intramuscularly every 2 months 1, 2
For vitamin B12 deficiency without neurological involvement, administer hydroxocobalamin 1 mg intramuscularly three times a week for 2 weeks, followed by maintenance treatment with 1 mg intramuscularly every 2-3 months for life 1, 2
Intramuscular administration is the preferred route for vitamin B12 replacement in cases of malabsorption 2
For patients with malabsorption causes, parenteral vitamin B12 will be required lifelong 2

Never administer folic acid before treating vitamin B12 deficiency, as it may mask underlying B12 deficiency and precipitate subacute combined degeneration of the spinal cord 3, 4
Before initiating folic acid treatment, check and treat for vitamin B12 deficiency 3, 4
For folic acid deficiency, administer oral folic acid 5 mg daily for a minimum of 4 months 3, 4
Further investigations are recommended if there is suspicion of malabsorption 3

Use either total B12 or active B12 as the initial test for B12 deficiency, and consider measuring methylmalonic acid as a confirmatory test when initial results are indeterminate 2
Check both vitamin B12 and folate levels, as deficiencies may coexist 2
Certain medications like anticonvulsants, sulfasalazine, and methotrexate may affect folate levels 4
In patients with chronic inflammation, ferritin levels may be falsely elevated, masking iron deficiency that may coexist with B12 or folate deficiency 4
For patients with unexplained anemia or fatigue that doesn't respond to B12 or folate treatment, investigate for other nutritional deficiencies including protein, zinc, copper, and selenium 3