From the Guidelines
High vitamin B12 levels are usually not a health concern and rarely require treatment, but unexpectedly high levels without supplementation should be evaluated by a healthcare provider to rule out underlying conditions. Elevated B12 can result from taking supplements or consuming B12-rich foods like meat, fish, eggs, and fortified products. However, high B12 can sometimes indicate underlying conditions such as liver disease, certain blood disorders like myeloproliferative disorders or leukemia, kidney disease, or certain cancers 1.
Key Considerations
- High B12 levels, typically above 900 pg/mL, are usually not toxic due to the body's ability to excrete excess water-soluble vitamins like B12.
- If you have unexpectedly high B12 levels without supplementation, consult your healthcare provider for evaluation.
- They may recommend stopping supplements if you're taking them, ordering additional tests to check for underlying conditions, or monitoring your levels over time.
- Certain symptoms like cognitive difficulties, eyesight problems, or abnormal blood count findings can be related to vitamin B12 deficiency, but high levels are not typically associated with these symptoms 1.
Evaluation and Management
- The healthcare provider may order additional tests to check for underlying conditions such as liver disease, blood disorders, kidney disease, or certain cancers.
- Stopping supplements or modifying diet may be recommended if high B12 levels are due to excessive intake.
- Monitoring B12 levels over time may be necessary to ensure that levels return to normal and to rule out any underlying conditions.
From the Research
High Vitamin B12 Levels
- High serum levels of vitamin B12, also known as hypervitaminemia B12, can be caused by various factors, including solid neoplasia, acute or chronic hematological diseases, liver disorders, and excess vitamin B12 intake 2.
- Other causes of high vitamin B12 levels include monoclonal gammapathy of undetermined significance, renal failure, inflammatory or autoimmune diseases, and transient hematological disorders such as neutrophilia and secondary eosinophilia 2.
- Hypervitaminemia B12 can be a frequent finding in general practice, and its clinical implications and associated disease entities need to be considered when this laboratory abnormality is found 3.
Disease Entities Associated with High Vitamin B12 Levels
- Solid neoplasia, primary or metastatic, can be associated with high vitamin B12 levels 2.
- Acute or chronic hematological diseases can also cause elevated vitamin B12 levels 2.
- Liver disorders, such as liver disease, can lead to high vitamin B12 levels 2.
- Monoclonal gammapathy of undetermined significance, renal failure, and inflammatory or autoimmune diseases can also be associated with high vitamin B12 levels 2.
Clinical Implications of High Vitamin B12 Levels
- High vitamin B12 levels can have various clinical implications, including an increased risk of certain diseases and conditions 3.
- The diagnosis and treatment of hypervitaminemia B12 require a comprehensive approach, considering the underlying causes and associated disease entities 3.
- Vitamin B12 deficiency, on the other hand, can lead to adverse health effects such as anemia and neurologic damage, and oral supplementation can be as effective as intramuscular injections in treating the deficiency 4.