Did your blood test show very high B12 levels?
We often get emails from concerned readers whose blood tests have returned with elevated B12 levels. We’re talking 1200, 1500, 2000, even 7500 pg/ml. Is there any reason for you to worry? And what does high vitamin B12 even mean?
Let’s answer these questions.
Causes of High B12 Levels In Blood
If your test shows excessive B12 levels – in the absence of supplementation – this may be a sign of liver disease or cell death (and the breakdown of tissues) that release the B12 back into your blood circulation. Therefore, hypercobalaminemia (high serum B12 levels) may be a warning sign of some serious underlying pathology:
The aetiological profile of high serum cobalamin predominantly encompasses severe disease entities for which early diagnosis is critical for prognosis. These entities are essentially comprised of solid neoplasms, haematological malignancies and liver and kidney diseases. This review reflects the potential importance of the vitamin B12 assay as an early diagnostic marker of these diseases. A codified approach is needed to determine the potential indications of a search for high serum cobalamin and the practical clinical strategy to adopt upon discovery of elevated cobalamin levels. While low serum cobalamin levels do not necessarily imply deficiency, an abnormally high serum cobalamin level forms a warning sign requiring exclusion of a number of serious underlying pathologies. Functional cobalamin deficiency can thus occur at any serum level.The pathophysiology of elevated vitamin B12 in clinical practice
Elevated levels of serum cobalamin may be a sign of a serious, even life-threatening, disease. Hematologic disorders like chronic myelogeneous leukemia, promyelocytic leukemia, polycythemia vera and also the hypereosinophilic syndrome can result in elevated levels of cobalamin. Not surprisingly, a rise of the cobalamin concentration in serum is one of the diagnostic criteria for the latter two diseases. The increase in circulating cobalamin levels is predominantly caused by enhanced production of haptocorrin. Several liver diseases like acute hepatitis, cirrhosis, hepatocellular carcinoma and metastatic liver disease can also be accompanied by an increase in circulating cobalamin. This phenomenon is predominantly caused by cobalamin release during hepatic cytolysis and/or decreased cobalamin clearance by the affected liver. Altogether it can be concluded that an observed elevation of cobalamin in blood merits the a full diagnostic work up to assess the presence of disease.SIGNIFICANCE OF ELEVATED COBALAMIN (VITAMIN B12) LEVELS IN BLOOD
However, if you’ve been supplementing, high B12 levels in the blood are completely normal. Remember, there are no toxicity levels. Most of the B12 gets flushed out in the urine; the rest is absorbed in the liver, kidneys and muscle tissues.
To illustrate, think about it this way:
When your test shows 1000pg/ml, only about 5μg floats around in your blood. Have a good B12-rich steak and your serum level shoots up to more than 1500pg/ml for a short duration. With our recommended methyl B12 injections, if you did a blood test right after a 1,200μg shot, you’d get a recorded level of ~250,000pg/ml for a few minutes! Inject two or three times a day and you’ll have high blood levels of B12 around the clock.
In such cases, high levels are absolutely normal.
So, are your vitamin B12 levels too high?
This may be because an illness like kidney failure, liver disease, or cancer is releasing the B12 back into the blood. Early diagnosis is key, so if you show excess B12 levels, go and have the tests done. Above all, concern yourself less with how to lower B12 levels, and more with how to mend yourself from the underlying disorder.
However, if you’re supplementing (and everything else is normal), then increased levels shouldn’t bother you. Your blood numbers are going to be high around the clock.
Hope that’s helpful.