From the Research
Elevated vitamin B12 levels without supplementation can occur due to several medical conditions, with liver disease being a common cause, as evidenced by a study published in 2023 1, which found that falsely elevated vitamin B12 levels are associated with the severity and prognosis of chronic liver disease.
Causes of Elevated Vitamin B12 Levels
The causes of elevated vitamin B12 levels without supplementation are varied and can include:
- Liver disease, which can cause the liver to release stored B12 into the bloodstream, as seen in a study published in 2017 2
- Certain blood disorders, such as myeloproliferative disorders, polycythemia vera, and chronic myelogenous leukemia, which can increase B12 levels due to excessive cell turnover
- Kidney disease, which can reduce the clearance of B12 from the blood
- Some cancers, particularly liver and kidney cancers, which can release stored B12
- Autoimmune conditions, such as Graves' disease, which can interfere with B12 binding proteins
- Certain medications, including metformin, oral contraceptives, and some antibiotics, which can affect B12 levels
- Genetic factors affecting B12 metabolism or transport proteins, which can cause elevated levels
Importance of Medical Evaluation
It is essential to note that high B12 levels are typically a marker of underlying conditions rather than a problem itself, and unexplained elevated B12 levels should prompt medical evaluation to identify the underlying cause, as highlighted in a review published in 2024 3, which found an association between elevated B12 and a higher risk of cancer.
Diagnostic Considerations
In cases of unexplained elevated B12 levels, diagnostic considerations should include testing for liver disease, blood disorders, kidney disease, and cancer, as well as evaluation for autoimmune conditions and genetic factors, as discussed in a study published in 2019 4.
Recent Evidence
A recent study published in 2024 5 highlighted the importance of considering macro-vitamin B12 as a cause of falsely elevated cobalamin levels, and the use of PEG precipitation to distinguish between "real" high vitamin B12 and macro-vitamin B12.