QuestionQUESTION: Hello Elizabeth, I am a 59-year old woman who recently had a routine blood test. Everything was in the normal range except for my RBC, which was low 3.95 (4.20 - 6.30). Also, my B12 was slightly high at 948 (211 - 946). My last two blood tests over the past year were basically the same. My doctor has never addressed the low RBC, but I would like to ask him about it at my next appointment. Can you please tell me what low RBC can mean when everything else is normal? Are there any particular questions I should ask my doctor? Here are some of my other results:
WBC 8.2 (4.1 - 10.9)
HGB 12.3 (11.4 - 15.0)
HCT 34.9 (34.0 - 45.0)
Iron 60 (60-150)
Everything else fell in the normal range. I thank you for your expertise.
ANSWER: Hi Ronnie,
Please be advised that this is not a substitute for medical advice. Your doctor is the best source of information and advice for your own specific health condition and treatment.
Below are the normal reference ranges.
panic values
http://www.stanfordlab.com/pages/panicvalues.htm
http://pathcuric1.swmed.edu/pathdemo/nrrt.htm
Reference ranges are averages based on patient populations and therefore can vary slightly from one patient population to another.
Normal reference ranges can vary among patients based upon a variety of factors, including the patient's age and sex.
Your RBC range is not a panic value, and is close to the normal range. Since you mentioned your other lab values are within reference range, is your doctor concerned?
Are you taking B12 supplements? Have you been diagnosed with any GI conditions such as Crohns disease, etc? Below is another possible cause of elevated B12 levels.
http://www.yourhealthbase.com/vitamin_B12.html
The normal blood level of vitamin B12 ranges between 200 and 600 picogram/milliliter (148-443 picomol/liter). Although deficiency is far more common than excess when it comes to vitamin B12 status cases have been reported where blood levels exceeded 3000 picograms/milliliter. Such high levels may be caused by bacterial overgrowth as outlined in the article Vitamin B-12 Overload
However given that your other results are within the normal range, you may want to ask your doctor about possible causes of the high B12 and RBC values in your specific situation.
Elizabeth
---------- FOLLOW-UP ----------
QUESTION: Hi Elizabeth, Thank you for your reply. You wrote that normal blood level of B12 ranges between 200 & 600 pg/mL. However, the range stated by the lab that did my test is 211-946 pg/mL. I tested at 948 which is just out of this range. I have never been diagnosed with any type of digestive disease not do I take B12 supplements. Can you please tell me why ranges of B12 in pg/mL vary so greatly (your values 200-600 pg/mL vs. my lab at 211-946 pg/mL)? Thank you again.
AnswerYou wrote that normal blood level of B12 ranges between 200 & 600 pg/mL. However, the range stated by the lab that did my test is 211-946 pg/mL.
I tested at 948 which is just out of this range. I have never been diagnosed with any type of digestive disease not do I take B12 supplements. Can you please tell me why ranges of B12 in pg/mL vary so greatly (your values 200-600 pg/mL vs. my lab at 211-946 pg/mL)?
[Elizabeth Response 9/21/2010]
Hi Ronnie,
Since reference ranges are averages based on patient populations and therefore can vary slightly from one patient population to another, it appears the lab that ran your test uses a different reference range.
You may want to ask your doctor why the serum B12 reference range for this lab is in the 211-946 pg/mL range.
Have you had elevated B12 levels on any previous lab results? It may be that for whatever reason your system is not clearing the B12, or it could have been an error in the testing procedure. Was the test rerun? The standard procedure for an abnormal lab value is to rerun it.
Since your result was 948 pg/mL, though it is not that far out of the normal range. What was the purpose for running the original lab tests?
If it was a routine annual physical exam, did you have a complete metabolic panel run along with this lab testing? If so, what was your Creatinine result?
Was your doctor concerned about the B12 result? If the B12 is rerun and the results are the same, depending on whether or not your doctor is concerned, you may want to ask your doctor to run a complete metabolic panel.
Elizabeth
