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Suggest An Accurate Test To Detect B12 Deficiency
Question: Hi, I have been b12 deficient for 6-7 years. The deficiency persisted from one year to the next in spite of the shots prescribed by the GP (there was no follow-up in the months following the b12 shots and there was never more than 1 bottle prescribed). Recently I have been having these neuromuscular symptoms (loss of balance, slight neck/head tremour,muscular weakness that I feel especially in the left arm and leg, + extreme fatigue), but my b12 level is surprinsigly in the normal range for the first time (NB: I have been taking sublingual b12 pills on and off before the last blood test). Can this be a false normal result hiding in fact the long-term deficiency that causes all these new symptoms? Are there more accurate tests to determine the deficiency?
Brief Answer:
Checking elevated Methylmalonic acid in urine , deficiency confirmed at B12 less then 100 pg/ml
Detailed Answer:
Hello and Welcome
I appreciate your concern
The test results need to be interpreted with respect to the clinical manifestations. A vitamin B12 level of less than 100 pg/mL is considered as diagnostic of vitamin B12 deficiency.
The significance of a vitamin B12 level of 100-400 pg/mL is not clear, and is interpreted with caution.
Vitamin B12 deficiency can results in megaloblastic anemia, peripheral neuropathy and/or dementia. Your levels are in normal range but the various neurological issues that you described need to be addressed.
Several Conditions can increase vitamin B12 levels and affect the labs , leading to a falsely elevated level... like Ingestion of vitamin A, C and estrogens, Hepatocellular damage (liver cell) , Myeloproliferative disorders (issues with bone marrow) and Uremia etc. If they aren't present , then its most likely that the B 12 level was not falsely normal especially in the context of the supplementation.
B 12 levels is a good indicator but for accurate testing you should go for Methylmalonic acid elevation in the urine. In vitamin B12 deficiency, methylmalonic acid and/or homocysteine levels are higher. If B12 level is between 100 and 400 pg/mL, methylmalonic acid and homocysteine levels should be checked for. If either is elevated, vitamin B12 is deficient in such a person.
wishing you best of health
thanks
Dr. M.S.Khalil
Checking elevated Methylmalonic acid in urine , deficiency confirmed at B12 less then 100 pg/ml
Detailed Answer:
Hello and Welcome
I appreciate your concern
The test results need to be interpreted with respect to the clinical manifestations. A vitamin B12 level of less than 100 pg/mL is considered as diagnostic of vitamin B12 deficiency.
The significance of a vitamin B12 level of 100-400 pg/mL is not clear, and is interpreted with caution.
Vitamin B12 deficiency can results in megaloblastic anemia, peripheral neuropathy and/or dementia. Your levels are in normal range but the various neurological issues that you described need to be addressed.
Several Conditions can increase vitamin B12 levels and affect the labs , leading to a falsely elevated level... like Ingestion of vitamin A, C and estrogens, Hepatocellular damage (liver cell) , Myeloproliferative disorders (issues with bone marrow) and Uremia etc. If they aren't present , then its most likely that the B 12 level was not falsely normal especially in the context of the supplementation.
B 12 levels is a good indicator but for accurate testing you should go for Methylmalonic acid elevation in the urine. In vitamin B12 deficiency, methylmalonic acid and/or homocysteine levels are higher. If B12 level is between 100 and 400 pg/mL, methylmalonic acid and homocysteine levels should be checked for. If either is elevated, vitamin B12 is deficient in such a person.
wishing you best of health
thanks
Dr. M.S.Khalil
Note: For more detailed guidance, please consult an Internal Medicine Specialist, with your latest reports. Click here..
Above answer was peer-reviewed by :
Dr. Vinay Bhardwaj
Answered by
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