Treatment of Vitamin B12 Deficiency in Children
Vitamin B12 deficiency in children should be treated with intramuscular hydroxocobalamin 1 mg three times weekly for 2 weeks, followed by maintenance therapy with 1 mg intramuscularly every 2-3 months lifelong for those without neurological involvement, while those with neurological symptoms require more intensive therapy with injections on alternate days until no further improvement is seen. 1
Diagnosis and Assessment
Before initiating treatment, proper diagnosis is essential:
Confirm vitamin B12 deficiency with serum levels:
- <180 ng/L indicates confirmed deficiency
- 180-350 ng/L is indeterminate
350 ng/L makes deficiency unlikely 1
For indeterminate cases or when clinical suspicion remains high despite normal levels, test methylmalonic acid and homocysteine levels 1
Assess for neurological involvement, which requires more aggressive treatment
Treatment Protocol
For Children with Neurological Involvement
- Hydroxocobalamin 1 mg intramuscularly on alternate days until no further improvement
- Then maintenance with 1 mg intramuscularly every 2-3 months lifelong 1
For Children without Neurological Involvement
- Hydroxocobalamin 1 mg intramuscularly three times weekly for 2 weeks
- Then maintenance with 1 mg intramuscularly every 2-3 months lifelong 1
Alternative Treatment Options
Recent evidence supports oral vitamin B12 as an effective alternative:
Oral high-dose supplementation (1000-2000 μg daily) is effective for most children without severe neurological involvement 1, 2, 3
Studies have shown that oral cyanocobalamin effectively normalizes vitamin B12 levels in children with nutritional deficiency 2, 3, 4
Sublingual administration (either methylcobalamin or cyanocobalamin) has also demonstrated efficacy comparable to intramuscular administration 1, 5
Special Considerations
For children with malabsorption conditions (e.g., ileal resection >20 cm, gastrointestinal pathology), parenteral administration is preferred 6, 7
Cyanocobalamin is FDA-approved for vitamin B12 deficiencies due to malabsorption associated with various conditions including:
- Addisonian (pernicious) anemia
- Gastrointestinal pathology or surgery
- Fish tapeworm infestation
- Malignancy of pancreas or bowel 7
Caution: Do not administer folic acid alone to patients with B12 deficiency as it may mask the anemia while allowing neurological damage to progress 1, 7
Monitoring Response
- Assess response after 3 months by measuring serum B12 levels 1
- Monitor hematological parameters (hematocrit, reticulocyte count) until normalization 7
- For patients with neurological symptoms, monitor for improvement in neurological function 1
Prevention in High-Risk Children
- Children following vegetarian or vegan diets should take regular B12 supplements or consume B12-fortified foods 1, 7
- Breastfed infants of vegetarian/vegan mothers are at risk even if mothers are asymptomatic and should receive supplementation 7
Treatment Efficacy
Research shows that both oral and parenteral formulations effectively normalize vitamin B12 levels in children with nutritional deficiency:
In a 2018 study, vitamin B12 levels increased from 183.5 ± 47 pg/mL to 482 ± 318.9 pg/mL with oral treatment and from 175.5 ± 42.5 pg/mL to 838 ± 547 pg/mL with parenteral treatment 2
Oral treatment may be considered as a safe first-line treatment for vitamin B12 deficiency in children, particularly for those with nutritional deficiency rather than malabsorption 2, 3, 4