From the Guidelines
Elevated Vitamin B12 levels are generally not considered harmful, but it's crucial to identify and address the underlying cause to prevent masking other deficiencies or indicating underlying health issues. To address Vitamin B12 elevation, no specific treatment is typically needed, but a thorough medical evaluation is recommended to determine the cause and rule out any serious conditions 1. Common causes of elevated B12 include:
- Excessive supplementation
- Liver disease
- Certain blood disorders (e.g., myeloproliferative disorders)
- Some medications (e.g., metformin) If you're taking B12 supplements, consider reducing or stopping them. For those with liver disease or blood disorders, treating the underlying condition is crucial. If medication-related, consult your doctor about potential alternatives. While high B12 itself isn't usually dangerous, it can mask other deficiencies or indicate underlying health issues, such as hyperhomocysteinemia, which is associated with a 2- to 3-fold increased risk for atherosclerotic vascular disease, including stroke 1. B12 is water-soluble, so excess amounts are typically excreted in urine. However, consistently high levels may indicate impaired metabolism or excretion, which warrants investigation. Regular monitoring of vitamin B12 levels is essential, especially for patients undergoing bariatric surgery, with a recommended frequency of monitoring at 3,6, and 12 months in the first year and at least annually thereafter 1. Maintaining a balanced diet and avoiding unnecessary supplementation is key to preventing B12 elevation in most cases.
From the Research
Implications of Elevated Vitamin B12 Levels
Elevated Vitamin B12 levels can have several implications, including:
- Association with underlying diseases such as hepatic disease, disseminated neoplasia, myeloproliferative disorders, and hypereosinophilic syndromes 2, 3
- Presence of immune complexes composed of IgG, IgM, and vitamin B12, which can lead to falsely elevated vitamin B12 concentrations 2, 4
- Indicator of potential significant morbidity, such as pancreatic tumour or lung adenocarcinoma 5, 6
- Need for prompt identification of the underlying cause to avoid delayed diagnosis and treatment 5
Causes of Elevated Vitamin B12 Levels
The causes of elevated vitamin B12 levels can be diverse, including:
- Over-supplementation with vitamin B12 3, 6
- Underlying diseases such as solid neoplasia, acute or chronic hematological diseases, liver disorders, and monoclonal gammapathy of undetermined significance 3
- Immune complexes, such as IgG-IgM-vitamin B12 immune complexes 2, 4
- Macro-vitamin B12, which can cause falsely elevated cobalamin levels 6
Diagnostic Approaches
To diagnose the cause of elevated vitamin B12 levels, several approaches can be used, including:
- Polyethylene glycol (PEG) precipitation to distinguish between "real" high vitamin B12 and macro-vitamin B12 6, 4
- Size exclusion chromatography to demonstrate the presence of immune complexes with plasma vitamin B12-binding proteins 2, 4
- ELISA methods to determine the presence of IgG-IgM immune complexes 2
- Imaging studies, such as X-ray, MRI, and CT scans, to identify underlying diseases such as tumours 5, 6