Ask the Nurse

Accidentally, it was discovered that my B12 blood test has been always running abnormally high. This has been since 2013 after a complete hysterectomy as I had an ovarian tumor removed which was of low malignant potential. Usually, it is running in the 1100s, and in 2014 was up to 3737. I was sent to a hemotologist who ran more blood tests and said he could find nothing wrong and perhaps my diet was so good that I run high. I do not eat red meat, but I do eat chicken, pork and fish. Now my primary doctor wants me to repeat going to an oncologist, but not sure if I should as blood cancers were ruled out last time I went. Any ideas?

The most common cause of high B12 in the blood is due to recent ingestion or injection of supplemental vitamin B12. We don't worry about overdosing on B12 supplements because excess can be excreted in your urine. It could also be possibly from your diet if high in animal products such as meat, eggs, and shellfish. However, it is extremely rare to have a high blood level from too much vitamin B12 in the diet.

There are cases where an individual has an elevated vitamin B12 level that is seen as an incidental finding in someone who has not recently received a vitamin B12 injection or taken a vitamin B12 supplement. Based on my review of the literature, limited observational studies have reported associations of increased vitamin B12 levels with other conditions and disease states, including:

  • Liver disease due to release of B12 from damaged liver cells into the bloodstream
  • Kidney disease due to impaired function of the kidneys to excrete excess B12
  • Increased levels of transcobalamin, which is a transporter of B12 in the bloodstream
  • Inflammatory conditions: rheumatoid arthritis, lupus
  • Hematologic (or blood) cancers: acute leukemia, multiple myeloma
  • Hematopoietic disorder: myeloproliferative neoplasm, myelodysplastic syndrome, hypereosinophilic syndrome, transient neutrophilia

As you can see, any of those I mentioned above could be a possibility. However, most of the medical conditions often present with other abnormal lab findings such as impaired kidney function, liver function, anemia, low white blood cell count and also other signs and symptoms of problems.

I recommend seeing a hematologist for a follow up evaluation to receive further review of your history, family history and further laboratory testing if appropriate, especially if the levels continue to be high.

Avoid supplements high in B12 for now, eat a varied healthy diet rich in fruits and vegetables and check to see if B12 is in any supplements you take.

All My Best,
Speaking of Women's Health Nurse

September 5, 2018 at 11:00am