Why would i have high b12 levels in my blood?

High intake: Since vitamins, by definition, are substances that we cannot make ourselves, a high level can only come from high intake. Vitamin B12 is not very toxic, but in high amounts can cause diarrhea, edema and increase risk of clots. If you are taking a vitamin B12 supplement, or injections you may want to cut back (discuss with your doctor if you are taking under a doctor's supervision).

Need more info: Conditions that can increase B12 level include: Inflammation Liver disease (such as cirrhosis or hepatitis) Myeloproliferative disorders (for example, polycythemia vera and chronic myelogenous leukemia)All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests.