1. If I have an elevated MMA, why might my doctor hesitate to diagnose me with vitamin B12 deficiency?
If your B12 test result is in the lower end of the normal range and you do not present with significant clinical symptoms, your healthcare provider may feel that you have adequate B12 and will rely on these findings rather than an elevated MMA. This may be especially true if your homocysteine level is normal. Your healthcare provider may want to monitor your condition over time and may be reluctant to start you on what could be lifelong treatment with B12 injections and/or oral supplementation unless it is truly necessary.
2. Can either blood or urine be used for the MMA test?
In most cases, it is okay to use blood or urine for this test. Sometimes, a healthcare provider may want to test both blood and urine in order to compare the MMA results. Since homocysteine is a blood test, it may be more efficient and convenient to draw blood for both the MMA and homocysteine tests when they are ordered together.
This article was last reviewed on September 25, 2015. | This article was last modified on September 25, 2015.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
The modified date indicates that one or more changes were made to the article. Such changes may or may not result from a full review of the article, so the two dates may not always agree.