In this article, we will look at what to do with high B12 levels. For instance we will look at what approaches you can take to find out:
How you can think about what's going on in your body to create high B12 levels?
Whether or not you actually have excess B12? Should you be checking your white blood cells, kidneys, liver etc. What test should you to be doing?

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The first thing you want to look at when you have high B12 levels is to find out why you have high B12 to begin with.  In previous 2 articles;What Does A High B12 level Mean?
Causes of High B12 Without Supplementation
we discussed this in some detail.  Still it is essential to find this out before you go on and start planning what to do about it.  One of the problems with finding out you have high B12 is that the serum B12 test gives limited information.  It is not the best at showing your true functional B12 status.  In other words, sometimes your tissues and cells do not have enough B12 and it does not match the results of the high serum test.  

This may seem strange that your tissues do not have enough B12 but the B12 blood test shows that you are high in B12.  However, you will get a get an appreciation for this as the article progresses.  The main point for now is that the serum B12 test is not the best way to understand your B12 status.  Neither are some of the functional tests like methylmalonic acid and homocysteine. 

If you do have adequate B12 levels, how do you know that there are not other problems with your white blood cells, with your kidneys, liver, etc? How do you know this is not a signal that's something deeper is going on with your tissues?
The first thing I recommend you do if you have a high B12 level, is find out if your cells are getting adequate B12 levels to begin with.  To do this, you want to run two tests called methylmalonic acid and homocysteine.  If these two test are normal (and the serum test is high) then you could likely assume that you do have adequate B12 levels.  By normal, for simplicity sake, we can use the lab reference range for normal.  So if normal, then you do have adequate B12 levels.  Keep in mind that there can be problems with these tests too, but all in all, if normal there is adequate B12. 
Another way to look at this is to distinguish if you do or do not have B12 deficiency symptoms, regardless if you have adequate B12 level per lab values.  If you have symptoms of B12 deficiency and your methylmalonic acid and homocysteine levels are high, then it's clear you want to treat for B12 deficiency.  However, you still should dig deeper, try to find out why the B12 level high and make sure that there's nothing more going on. On the other hand, if your homocysteine and methylmalonic are low (or normal) but you still have B12 deficiency symptoms, you may still want to treat for B12 deficiency.  There are various ways to go about that.  However, in the case that your labs are showing normal homocysteine and methylmalonic acid, then use more caution using B12 and focus more on finding the cause (see below).  The main reason for this distinction is that the symptoms of b12 deficiency can have many different causes.In the first case you have elevated B12, high homocysteine, high methylmalonic acid with B12 symptoms.  Here you will be you're treating for B12 deficiency.  In addition you want to make sure your white blood cells, your liver, your kidneys are al normal.  This could be done through some simple standard labs called a CBC and Chemistry panel.    If it's way outside the range, then there may be a problem there and you need to look a little closer.  If it all looks looks fine then probably there's nothing going on with these organs and tissues currently.  Regardless if it looks fine now, you should still be following a doctor and still looking at these tests on a regular basis.  While the levels could be normal now they may become abnormal later. 
If all tests are normal and you avoid extra B12 supplements for 6 months, you could start supplementing with B12. For both these scenarios, there are other test you can do to possibly uncover another layer of information.  There is a test called holotranscobalamin.