From the Guidelines
Vitamin B12 deficiency should be treated immediately with hydroxocobalamin 1 mg intramuscularly, with the treatment regimen depending on the presence of neurological involvement. The treatment approach varies based on whether the patient has neurological symptoms, such as unexplained sensory and/or motor and gait symptoms, or not. For patients with neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered on alternate days until there is no further improvement, then hydroxocobalamin 1 mg intramuscularly every 2 months 1. This is crucial because folic acid supplementation may mask severe vitamin B12 depletion and precipitate subacute combined degeneration of the spinal cord.
For individuals without neurological involvement, the recommended treatment is 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. It's essential to seek urgent specialist advice from a neurologist and haematologist if there's possible neurological involvement. Regular monitoring through blood tests is vital to ensure vitamin B12 levels return to normal and remain stable, especially for those requiring long-term treatment. The body stores vitamin B12, so deficiency symptoms develop gradually as stores deplete, and most people tolerate B12 well with minimal side effects, with excess B12 typically excreted in urine.
Key points to consider in vitamin B12 treatment include:
- Immediate treatment of vitamin B12 deficiency to prevent further complications
- Differentiation in treatment approach based on the presence of neurological symptoms
- Importance of not giving folic acid first as it may mask underlying vitamin B12 deficiency
- Lifelong maintenance treatment for many patients to prevent recurrence of deficiency
- Regular monitoring of vitamin B12 levels to adjust treatment as necessary 1.
From the FDA Drug Label
PRECAUTIONS General Vitamin B12 deficiency that is allowed to progress for longer than 3 months may produce permanent degenerative lesions of the spinal cord. Information for Patients Patients with pernicious anemia should be informed that they will require monthly injections of vitamin B12 for the remainder of their lives. The need for vitamin B12 is increased by pregnancy and lactation.
Treatment for B12 deficiency involves monthly injections of vitamin B12 for patients with pernicious anemia.
- Patients with pernicious anemia will require monthly injections of vitamin B12 for the rest of their lives.
- Pregnancy and lactation increase the need for vitamin B12.
- Failure to treat B12 deficiency can result in permanent degenerative lesions of the spinal cord 2.
From the Research
B12 Treatment Overview
- Vitamin B12 deficiency can be treated with oral or parenteral (intramuscular) supplementation 3, 4, 5, 6, 7.
- The choice of treatment depends on the cause of the deficiency, with oral supplementation suitable for reduced dietary intake and parenteral supplementation preferred for malabsorption 4, 5, 6.
Treatment Regimens
- Parenteral regimens may use 1000 micrograms cyanocobalamin, with 5 or 6 biweekly injections for loading and once-a-month for maintenance 3.
- Oral therapy with 300-1000 micrograms per day may be therapeutically equivalent to parenteral therapy 3.
- Some individuals may require individualized injection regimens with more frequent administration to remain symptom-free and maintain a normal quality of life 4.
Forms of Vitamin B12
- Vitamin B12 has two active co-enzyme forms, methylcobalamin and adenosylcobalamin, which have distinct metabolic fates and functions 6.
- Treatment of vitamin B12 deficiency may involve a combination of methylcobalamin and adenosylcobalamin or hydroxocobalamin 6.