From the Guidelines
Vitamin B12 injections are recommended for individuals with B12 deficiency, with the standard treatment involving intramuscular injections of hydroxocobalamin 1 mg on alternate days until there is no further improvement, then 1 mg every 2 months for patients with neurological involvement, and 1 mg three times a week for 2 weeks followed by maintenance treatment with 1 mg every 2-3 months for life for patients without neurological involvement 1.
Treatment Regimen
The treatment regimen for vitamin B12 deficiency varies depending on the presence of neurological involvement.
- For patients with neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered on alternate days until there is no further improvement, then 1 mg every 2 months 1.
- For patients without neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered three times a week for 2 weeks, followed by maintenance treatment with 1 mg every 2-3 months for life 1.
Important Considerations
It is essential to treat vitamin B12 deficiency immediately, especially in patients with possible neurological involvement, and to seek urgent specialist advice from a neurologist and haematologist if necessary 1.
- Folic acid deficiency may indicate non-adherence with daily multivitamin and mineral supplements or malabsorption, and treatment with oral folic acid 5 mg daily should be given for a minimum of 4 months after excluding vitamin B12 deficiency 1.
- Vitamin B12 injections are generally well-tolerated, with minimal side effects, including pain at the injection site, mild diarrhea, or itching 1.
Screening and Prevention
CD patients with ileal involvement and/or resection and/or clinical deficiency features should be screened yearly for B12 deficiency 1.
- Patients with more than 20 cm of ileum resected should receive 1000 mg of vitamin B12 prophylactically every month and indefinitely 1.
From the FDA Drug Label
CLINICAL PHARMACOLOGY Vitamin B12 is essential to growth, cell reproduction, hematopoiesis, and nucleoprotein and myelin synthesis. Cyanocobalamin is quantitatively and rapidly absorbed from intramuscular and subcutaneous sites of injection; the plasma level of the compound reaches its peak within 1 hour after intramuscular injection
- The B12 injection is absorbed quickly, with peak plasma levels reached within 1 hour after intramuscular injection 2.
- Cyanocobalamin and hydroxocobalamin are two forms of vitamin B12 that can be administered via injection, with cyanocobalamin being the most widely used form 2 and hydroxocobalamin being equally effective 3.
From the Research
Vitamin B12 Injection
- Vitamin B12 deficiency is a common condition that can be treated with injections or oral supplements 4, 5, 6, 7, 8
- Studies have shown that high-dose oral vitamin B12 (1000-2000 mcg) is as effective as intramuscular injections in achieving hematological and neurological responses 5, 6, 7
- The route of administration, whether oral or intramuscular, does not affect the efficacy of vitamin B12 treatment 6, 7, 8
- Sublingual administration of vitamin B12 has been shown to be effective and even superior to intramuscular injections in some cases 8
Dosage and Administration
- The recommended dosage for vitamin B12 injections is 1000 micrograms, with 5-6 biweekly injections for loading and once-a-month for maintenance 4
- Oral therapy with 300-1000 micrograms per day may be therapeutically equivalent to parenteral therapy 4
- High-dose oral vitamin B12 (1-2 mg daily) is as effective as intramuscular administration for correcting anemia and neurologic symptoms 7
Patient Considerations
- Screening for vitamin B12 deficiency may be warranted in patients with risk factors such as gastric or small intestine resections, inflammatory bowel disease, or use of certain medications 7
- Patients older than 50 years and vegans or strict vegetarians should consume foods fortified with vitamin B12 or take vitamin B12 supplements to improve absorption rates 7
- Patients who have had bariatric surgery should receive 1 mg of oral vitamin B12 per day indefinitely 7