No I don't think so.
You don't really absorb that much from the doses you are taking.
B12 does improve energy in some people...but we see that mostly from the day of the injections.
You might discuss the heart effects with your doctor to see if there is anything there.
You can reduce to 1000 mcg a day and see if that changes anything. Once people get up to proper levels, the really high dose is no longer needed. But whatever caused you to get low in the first place is probably still there. You will need some supplement for life perhaps, and if you do it on a regular basis, you won't get low again.
But that is good news that you are feeling better generally. Congratulations on that improvement!
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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